Topics

TDS3044B repair


Tom B
 

Hello All,

I am working on a TDS3044B that just has a white screen.  Nothing else comes up on the display.   The controls seem to respond, that is, the lights go on and off and there are relay clicks when I hit the Auto Set button.  The service manual is not much help.  The manual also does not tell you what the test points do.  I don't want to buy a new display unless necessary.  Anybody got advice on where to start?

Tom Bryan


Dave Casey
 

Check the ribbon cable between the display and the motherboard. Make sure
it's seated all the way.

Dave Casey

On Sat, Oct 26, 2019 at 9:50 PM Tom B <tbryan@...> wrote:

Hello All,

I am working on a TDS3044B that just has a white screen. Nothing else
comes up on the display. The controls seem to respond, that is, the
lights go on and off and there are relay clicks when I hit the Auto Set
button. The service manual is not much help. The manual also does not
tell you what the test points do. I don't want to buy a new display
unless necessary. Anybody got advice on where to start?

Tom Bryan






Ken Eckert
 

I concur with Dave, I had 2 scopes that the cable was not seated
correctly, same symptoms

Ken

On Saturday, October 26, 2019, Dave Casey <polara413@...> wrote:

Check the ribbon cable between the display and the motherboard. Make sure
it's seated all the way.

Dave Casey

On Sat, Oct 26, 2019 at 9:50 PM Tom B <tbryan@...> wrote:

Hello All,

I am working on a TDS3044B that just has a white screen. Nothing else
comes up on the display. The controls seem to respond, that is, the
lights go on and off and there are relay clicks when I hit the Auto Set
button. The service manual is not much help. The manual also does not
tell you what the test points do. I don't want to buy a new display
unless necessary. Anybody got advice on where to start?

Tom Bryan








Tom B
 

Hi Dave and Ken,

I checked the cable at both ends.  The main board end has a plastic clamp on J500 that I can't remove to pull the connector off unless I pull out the main board.  I pushed the connector down and it didn't move, so I think it is seated correctly.   The LCD end I can reach, and it feels like it is seated firmly.   If I have to I can pull the main board but I was hoping to rule out a few other things before I do that.  Unfortunately, I don't have the VGA module to test and see if the scope is working but the functioning of the controls tells me that most of it is.  Any other suggestions?

Tom

On 10/27/2019 11:19 AM, Ken Eckert wrote:
I concur with Dave, I had 2 scopes that the cable was not seated
correctly, same symptoms

Ken

On Saturday, October 26, 2019, Dave Casey <polara413@...> wrote:

Check the ribbon cable between the display and the motherboard. Make sure
it's seated all the way.

Dave Casey

On Sat, Oct 26, 2019 at 9:50 PM Tom B <tbryan@...> wrote:

Hello All,

I am working on a TDS3044B that just has a white screen. Nothing else
comes up on the display. The controls seem to respond, that is, the
lights go on and off and there are relay clicks when I hit the Auto Set
button. The service manual is not much help. The manual also does not
tell you what the test points do. I don't want to buy a new display
unless necessary. Anybody got advice on where to start?


Dave Casey
 

I've never actually seen one with the cable clamp installed, but I'm
surprised it can't be removed without removing the mainboard. Still,
pulling the mainboard is not very difficult. Once you've done it once, it's
a five minute operation. The cable itself could be bad, but you won't know
unless you remove it. Have you tried moving it with the scope on to see if
you can elicit a change in behavior on the display?

Dave Casey

On Sun, Oct 27, 2019 at 10:38 AM Tom B <tbryan@...> wrote:

Hi Dave and Ken,

I checked the cable at both ends. The main board end has a plastic
clamp on J500 that I can't remove to pull the connector off unless I
pull out the main board. I pushed the connector down and it didn't
move, so I think it is seated correctly. The LCD end I can reach, and
it feels like it is seated firmly. If I have to I can pull the main
board but I was hoping to rule out a few other things before I do that.
Unfortunately, I don't have the VGA module to test and see if the scope
is working but the functioning of the controls tells me that most of it
is. Any other suggestions?

Tom


On 10/27/2019 11:19 AM, Ken Eckert wrote:
I concur with Dave, I had 2 scopes that the cable was not seated
correctly, same symptoms

Ken

On Saturday, October 26, 2019, Dave Casey <polara413@...> wrote:

Check the ribbon cable between the display and the motherboard. Make
sure
it's seated all the way.

Dave Casey

On Sat, Oct 26, 2019 at 9:50 PM Tom B <tbryan@...> wrote:

Hello All,

I am working on a TDS3044B that just has a white screen. Nothing else
comes up on the display. The controls seem to respond, that is, the
lights go on and off and there are relay clicks when I hit the Auto Set
button. The service manual is not much help. The manual also does not
tell you what the test points do. I don't want to buy a new display
unless necessary. Anybody got advice on where to start?



Oz-in-DFW
 

I'd still remove and reseat both ends.

Where are you in the world? I have a VGA/serial/GPIB card in my 3014 that we might be able to mate with your scope briefly.


Tom B
 

Hi Dave,

The clip is used on the B models. The plain version does not have it.  The clip cannot be moved far enough to remove the connector without pulling the main board.  I may try that when I have time. I have tried fiddling with the cable but there is no reaction on the screen.  It just stays white.

Tom

On 10/28/2019 12:21 AM, Dave Casey wrote:
I've never actually seen one with the cable clamp installed, but I'm
surprised it can't be removed without removing the mainboard. Still,
pulling the mainboard is not very difficult. Once you've done it once, it's
a five minute operation. The cable itself could be bad, but you won't know
unless you remove it. Have you tried moving it with the scope on to see if
you can elicit a change in behavior on the display?

Dave Casey

On Sun, Oct 27, 2019 at 10:38 AM Tom B <tbryan@...> wrote:


Tom B
 

Hi Rich (?),

Thanks. I am located in Maryland near Washington DC.

If anyone in the Washington DC area has a TDS3GV that I could come over and quickly test my scope with, I would appreciate it.

Tom Bryan
N3AJA

On 10/28/2019 10:29 AM, Oz-in-DFW wrote:
I'd still remove and reseat both ends.

Where are you in the world? I have a VGA/serial/GPIB card in my 3014 that we might be able to mate with your scope briefly.


David Kuhn
 

I'm in central, PA, about 3 hours from you if you ever want to come up and
try it here with one of my VGA/GPIB modules.

Before that. Power it up while holding in the "B TRIG" button (might be
different on the TDS3014), which on my TDS3032's causes a RESET. I've had
that fix display issues after replacing the battery NVRAM in in the scope.

The display in the TDS3032, is the exact same LCD used in the GEIT Phasor
XS and USN60 instruments. I have worked on many. I have never seen the
LCD fail on those instrument where it's all white. Typical, if not broken,
is smeary displays that lines seems to go out of sync. Dim, of course with
broken backlight tubes.

Dave

On Mon, Oct 28, 2019 at 10:50 PM Tom B <tbryan@...> wrote:

Hi Rich (?),

Thanks. I am located in Maryland near Washington DC.

If anyone in the Washington DC area has a TDS3GV that I could come over
and quickly test my scope with, I would appreciate it.

Tom Bryan
N3AJA


On 10/28/2019 10:29 AM, Oz-in-DFW wrote:
I'd still remove and reseat both ends.

Where are you in the world? I have a VGA/serial/GPIB card in my 3014
that we might be able to mate with your scope briefly.



Tom B
 

Hi Dave,

I  tried the "B Trig" and nothing happened.  Displays are fairly cheap but I don't want to buy one unless I have to.

Thank you for the offer.  I would be a long while before I make it up that way.

What town are you in?

Tom

On 10/29/2019 4:52 PM, David Kuhn wrote:
I'm in central, PA, about 3 hours from you if you ever want to come up and
try it here with one of my VGA/GPIB modules.

Before that. Power it up while holding in the "B TRIG" button (might be
different on the TDS3014), which on my TDS3032's causes a RESET. I've had
that fix display issues after replacing the battery NVRAM in in the scope.

The display in the TDS3032, is the exact same LCD used in the GEIT Phasor
XS and USN60 instruments. I have worked on many. I have never seen the
LCD fail on those instrument where it's all white. Typical, if not broken,
is smeary displays that lines seems to go out of sync. Dim, of course with
broken backlight tubes.

Dave

On Mon, Oct 28, 2019 at 10:50 PM Tom B <tbryan@...> wrote:

Hi Rich (?),

Thanks. I am located in Maryland near Washington DC.

If anyone in the Washington DC area has a TDS3GV that I could come over
and quickly test my scope with, I would appreciate it.

Tom Bryan
N3AJA


On 10/28/2019 10:29 AM, Oz-in-DFW wrote:
I'd still remove and reseat both ends.

Where are you in the world? I have a VGA/serial/GPIB card in my 3014
that we might be able to mate with your scope briefly.



David Kuhn
 

Sorry for the response delay.

I am in Lewistown, PA. How cheap are the displays and where are you
finding them? I have found the ones, used in the Ultrasonic instruments I
mentioned, on Alliexpress, and EBAY (haven't ordered any from either one),
but I can not find the backlight tubes, which I find is usually the problem
with the displays. The displays may be just slightly different than in the
TDS3032, but if so, only mechanically. The connectors are the same, and I
really think the part numbers are the same. It's not a real easy
replacement in those TDS scopes. It looks easy, but it's a pain in the
butt.

You may want to buy the TDS3GV on EBAY. I can't use a TDS3032 without one,
but I have written a lot of service software in VBA and VB6 that
automatically sets up the scopes and gets data from them. I can also
project my TDS3032 to the 32" TV mounted on the wall above it (an older
Sceptre with VGA input) and that's pretty cool.

Again, if the cables are seated well, I doubt the LCD is bad with an
all-white display. My thoughts are a main PCB issue. A TSD3GV could prove
me wrong.

Dave

On Tue, Oct 29, 2019 at 10:55 PM Tom B <tbryan@...> wrote:

Hi Dave,

I tried the "B Trig" and nothing happened. Displays are fairly cheap
but I don't want to buy one unless I have to.

Thank you for the offer. I would be a long while before I make it up
that way.

What town are you in?

Tom

On 10/29/2019 4:52 PM, David Kuhn wrote:
I'm in central, PA, about 3 hours from you if you ever want to come up
and
try it here with one of my VGA/GPIB modules.

Before that. Power it up while holding in the "B TRIG" button (might be
different on the TDS3014), which on my TDS3032's causes a RESET. I've
had
that fix display issues after replacing the battery NVRAM in in the
scope.

The display in the TDS3032, is the exact same LCD used in the GEIT Phasor
XS and USN60 instruments. I have worked on many. I have never seen the
LCD fail on those instrument where it's all white. Typical, if not
broken,
is smeary displays that lines seems to go out of sync. Dim, of course
with
broken backlight tubes.

Dave

On Mon, Oct 28, 2019 at 10:50 PM Tom B <tbryan@...> wrote:

Hi Rich (?),

Thanks. I am located in Maryland near Washington DC.

If anyone in the Washington DC area has a TDS3GV that I could come over
and quickly test my scope with, I would appreciate it.

Tom Bryan
N3AJA


On 10/28/2019 10:29 AM, Oz-in-DFW wrote:
I'd still remove and reseat both ends.

Where are you in the world? I have a VGA/serial/GPIB card in my 3014
that we might be able to mate with your scope briefly.






Harvey White
 

On 11/5/2019 1:59 PM, David Kuhn wrote:
Sorry for the response delay.

I am in Lewistown, PA. How cheap are the displays and where are you
finding them? I have found the ones, used in the Ultrasonic instruments I
mentioned, on Alliexpress, and EBAY (haven't ordered any from either one),
but I can not find the backlight tubes, which I find is usually the problem
with the displays. The displays may be just slightly different than in the
TDS3032, but if so, only mechanically. The connectors are the same, and I
really think the part numbers are the same. It's not a real easy
replacement in those TDS scopes. It looks easy, but it's a pain in the
butt.
Depending on the manufacturer of the display, there are commercially available LED backlight kits to replace the CCFL lamps.

You may want to buy the TDS3GV on EBAY. I can't use a TDS3032 without one,
but I have written a lot of service software in VBA and VB6 that
automatically sets up the scopes and gets data from them. I can also
project my TDS3032 to the 32" TV mounted on the wall above it (an older
Sceptre with VGA input) and that's pretty cool.

Again, if the cables are seated well, I doubt the LCD is bad with an
all-white display. My thoughts are a main PCB issue. A TSD3GV could prove
me wrong.
If you find an all white display, then depending on the type of display (positive or negative) you'd suspect no signals to it, or improper signals.

The display is likely to take either 5 or 3.3 volts, recent ones that I have take 3.3.  Older STN displays can take 5.  The white is the result of the backlight working, but no active pixels at all (hence no polarization, etc....).

Like a CRT display, you'll be looking for a horizontal sync (at perhaps 30 Khz), vertical sync (say 60 or so Hz), a DE (likely at horizontal rate and active high), and a pixel clock at about 25 or so Mhz.  You'd also expect supply voltages to be somewhere on the display.  If the timing is right and the voltages are there, then the display ought to be showing something.  If not, then look at the other pins, they should be R,G,B digital signals, either in 565 (for a 16 bit panel) or 666 (for an 18 bit panel).  If there's any activity on them, then with the right sync signals, they ought to be giving something on the display.

Harvey




Dave

On Tue, Oct 29, 2019 at 10:55 PM Tom B <tbryan@...> wrote:

Hi Dave,

I tried the "B Trig" and nothing happened. Displays are fairly cheap
but I don't want to buy one unless I have to.

Thank you for the offer. I would be a long while before I make it up
that way.

What town are you in?

Tom

On 10/29/2019 4:52 PM, David Kuhn wrote:
I'm in central, PA, about 3 hours from you if you ever want to come up
and
try it here with one of my VGA/GPIB modules.

Before that. Power it up while holding in the "B TRIG" button (might be
different on the TDS3014), which on my TDS3032's causes a RESET. I've
had
that fix display issues after replacing the battery NVRAM in in the
scope.
The display in the TDS3032, is the exact same LCD used in the GEIT Phasor
XS and USN60 instruments. I have worked on many. I have never seen the
LCD fail on those instrument where it's all white. Typical, if not
broken,
is smeary displays that lines seems to go out of sync. Dim, of course
with
broken backlight tubes.

Dave

On Mon, Oct 28, 2019 at 10:50 PM Tom B <tbryan@...> wrote:

Hi Rich (?),

Thanks. I am located in Maryland near Washington DC.

If anyone in the Washington DC area has a TDS3GV that I could come over
and quickly test my scope with, I would appreciate it.

Tom Bryan
N3AJA


On 10/28/2019 10:29 AM, Oz-in-DFW wrote:
I'd still remove and reseat both ends.

Where are you in the world? I have a VGA/serial/GPIB card in my 3014
that we might be able to mate with your scope briefly.





David Kuhn
 

" there are commercially
available LED backlight kits to replace the CCFL lamps. "

I would be in your dept if you could point me to an LED replacement for the
fluorescent tubes in the NEC displays like that are used in the TDS3000
series (no bloody A, No bloody B or C). I'll get the actual NEC LCD part
number and reply again later. I wonder if the LED replacement is made to
run off the fluorescent tube inverter supply? I ask that because that
supply has software control line to control the brightness. LET is
probably off or on, unless it is designed to run off the inverter or a
software equivalent inverter is available (retrofitting old equipment not
designing new stuff).

dave

On Tue, Nov 5, 2019 at 2:31 PM Harvey White <madyn@...> wrote:


On 11/5/2019 1:59 PM, David Kuhn wrote:
Sorry for the response delay.

I am in Lewistown, PA. How cheap are the displays and where are you
finding them? I have found the ones, used in the Ultrasonic instruments
I
mentioned, on Alliexpress, and EBAY (haven't ordered any from either
one),
but I can not find the backlight tubes, which I find is usually the
problem
with the displays. The displays may be just slightly different than in
the
TDS3032, but if so, only mechanically. The connectors are the same, and
I
really think the part numbers are the same. It's not a real easy
replacement in those TDS scopes. It looks easy, but it's a pain in the
butt.
Depending on the manufacturer of the display, there are commercially
available LED backlight kits to replace the CCFL lamps.

You may want to buy the TDS3GV on EBAY. I can't use a TDS3032 without
one,
but I have written a lot of service software in VBA and VB6 that
automatically sets up the scopes and gets data from them. I can also
project my TDS3032 to the 32" TV mounted on the wall above it (an older
Sceptre with VGA input) and that's pretty cool.

Again, if the cables are seated well, I doubt the LCD is bad with an
all-white display. My thoughts are a main PCB issue. A TSD3GV could
prove
me wrong.
If you find an all white display, then depending on the type of display
(positive or negative) you'd suspect no signals to it, or improper signals.

The display is likely to take either 5 or 3.3 volts, recent ones that I
have take 3.3. Older STN displays can take 5. The white is the result
of the backlight working, but no active pixels at all (hence no
polarization, etc....).

Like a CRT display, you'll be looking for a horizontal sync (at perhaps
30 Khz), vertical sync (say 60 or so Hz), a DE (likely at horizontal
rate and active high), and a pixel clock at about 25 or so Mhz. You'd
also expect supply voltages to be somewhere on the display. If the
timing is right and the voltages are there, then the display ought to be
showing something. If not, then look at the other pins, they should be
R,G,B digital signals, either in 565 (for a 16 bit panel) or 666 (for an
18 bit panel). If there's any activity on them, then with the right
sync signals, they ought to be giving something on the display.

Harvey




Dave

On Tue, Oct 29, 2019 at 10:55 PM Tom B <tbryan@...> wrote:

Hi Dave,

I tried the "B Trig" and nothing happened. Displays are fairly cheap
but I don't want to buy one unless I have to.

Thank you for the offer. I would be a long while before I make it up
that way.

What town are you in?

Tom

On 10/29/2019 4:52 PM, David Kuhn wrote:
I'm in central, PA, about 3 hours from you if you ever want to come up
and
try it here with one of my VGA/GPIB modules.

Before that. Power it up while holding in the "B TRIG" button (might
be
different on the TDS3014), which on my TDS3032's causes a RESET. I've
had
that fix display issues after replacing the battery NVRAM in in the
scope.
The display in the TDS3032, is the exact same LCD used in the GEIT
Phasor
XS and USN60 instruments. I have worked on many. I have never seen
the
LCD fail on those instrument where it's all white. Typical, if not
broken,
is smeary displays that lines seems to go out of sync. Dim, of course
with
broken backlight tubes.

Dave

On Mon, Oct 28, 2019 at 10:50 PM Tom B <tbryan@...> wrote:

Hi Rich (?),

Thanks. I am located in Maryland near Washington DC.

If anyone in the Washington DC area has a TDS3GV that I could come
over
and quickly test my scope with, I would appreciate it.

Tom Bryan
N3AJA


On 10/28/2019 10:29 AM, Oz-in-DFW wrote:
I'd still remove and reseat both ends.

Where are you in the world? I have a VGA/serial/GPIB card in my 3014
that we might be able to mate with your scope briefly.








Harvey White
 

This is the first item that came up when searching for CCFL LED replacements

https://www.ccflwarehouse.com/

no idea if they have anything that will fit.

I have made CCFL replacement strips for some odd displays, the older Optrex DSTN color displays and the FG0800 8 inch VGA display.

Due to the lack of 12 volts in a battery operated project, all of them are designed to run the LEDS in parallel, at about 15 ma per led, about 9 per 4 inch strip.  The strips are designed to be stacked, resulting in parallel operation.

Whether or not the lamps can be reasonably replaced depends on the manufacturer.  In the Optrex displays, remove a screw, swing a shield aside, and pull out the tube.  In the FG0800, it's more involved (and takes 4 strips), even more if you wanted the side. The silly tube is a top, left, and bottom assembly.

The replacement should be made to run off the (suspect 12 volts) supply, and a simple PWM would easily replace the inverter.  I'm sure it varies wildly.

I know there's a market out there, and the more common the display, perhaps the easier it is to find the LED replacement,  or even the tube itself (which I'd recommend unless you want to go LED).

I went LED because the power consumption in battery operated equipment goes down by 50 to 75%, and I'm not happy with 1600 volts running around an experimental setup.

So give these people a try, they seem to be going laptop, so no idea what else they do.


You might also want to look here:

https://www.plazmo.com/collections/raw-ccfl-lamps/products/ccfl-backlight-for-tds3000-oscilloscope

10 dollars.

Harvey

On 11/6/2019 10:03 AM, David Kuhn wrote:
" there are commercially
available LED backlight kits to replace the CCFL lamps. "

I would be in your dept if you could point me to an LED replacement for the
fluorescent tubes in the NEC displays like that are used in the TDS3000
series (no bloody A, No bloody B or C). I'll get the actual NEC LCD part
number and reply again later. I wonder if the LED replacement is made to
run off the fluorescent tube inverter supply? I ask that because that
supply has software control line to control the brightness. LET is
probably off or on, unless it is designed to run off the inverter or a
software equivalent inverter is available (retrofitting old equipment not
designing new stuff).

dave

On Tue, Nov 5, 2019 at 2:31 PM Harvey White <madyn@...> wrote:

On 11/5/2019 1:59 PM, David Kuhn wrote:
Sorry for the response delay.

I am in Lewistown, PA. How cheap are the displays and where are you
finding them? I have found the ones, used in the Ultrasonic instruments
I
mentioned, on Alliexpress, and EBAY (haven't ordered any from either
one),
but I can not find the backlight tubes, which I find is usually the
problem
with the displays. The displays may be just slightly different than in
the
TDS3032, but if so, only mechanically. The connectors are the same, and
I
really think the part numbers are the same. It's not a real easy
replacement in those TDS scopes. It looks easy, but it's a pain in the
butt.
Depending on the manufacturer of the display, there are commercially
available LED backlight kits to replace the CCFL lamps.
You may want to buy the TDS3GV on EBAY. I can't use a TDS3032 without
one,
but I have written a lot of service software in VBA and VB6 that
automatically sets up the scopes and gets data from them. I can also
project my TDS3032 to the 32" TV mounted on the wall above it (an older
Sceptre with VGA input) and that's pretty cool.

Again, if the cables are seated well, I doubt the LCD is bad with an
all-white display. My thoughts are a main PCB issue. A TSD3GV could
prove
me wrong.
If you find an all white display, then depending on the type of display
(positive or negative) you'd suspect no signals to it, or improper signals.

The display is likely to take either 5 or 3.3 volts, recent ones that I
have take 3.3. Older STN displays can take 5. The white is the result
of the backlight working, but no active pixels at all (hence no
polarization, etc....).

Like a CRT display, you'll be looking for a horizontal sync (at perhaps
30 Khz), vertical sync (say 60 or so Hz), a DE (likely at horizontal
rate and active high), and a pixel clock at about 25 or so Mhz. You'd
also expect supply voltages to be somewhere on the display. If the
timing is right and the voltages are there, then the display ought to be
showing something. If not, then look at the other pins, they should be
R,G,B digital signals, either in 565 (for a 16 bit panel) or 666 (for an
18 bit panel). If there's any activity on them, then with the right
sync signals, they ought to be giving something on the display.

Harvey



Dave

On Tue, Oct 29, 2019 at 10:55 PM Tom B <tbryan@...> wrote:

Hi Dave,

I tried the "B Trig" and nothing happened. Displays are fairly cheap
but I don't want to buy one unless I have to.

Thank you for the offer. I would be a long while before I make it up
that way.

What town are you in?

Tom

On 10/29/2019 4:52 PM, David Kuhn wrote:
I'm in central, PA, about 3 hours from you if you ever want to come up
and
try it here with one of my VGA/GPIB modules.

Before that. Power it up while holding in the "B TRIG" button (might
be
different on the TDS3014), which on my TDS3032's causes a RESET. I've
had
that fix display issues after replacing the battery NVRAM in in the
scope.
The display in the TDS3032, is the exact same LCD used in the GEIT
Phasor
XS and USN60 instruments. I have worked on many. I have never seen
the
LCD fail on those instrument where it's all white. Typical, if not
broken,
is smeary displays that lines seems to go out of sync. Dim, of course
with
broken backlight tubes.

Dave

On Mon, Oct 28, 2019 at 10:50 PM Tom B <tbryan@...> wrote:

Hi Rich (?),

Thanks. I am located in Maryland near Washington DC.

If anyone in the Washington DC area has a TDS3GV that I could come
over
and quickly test my scope with, I would appreciate it.

Tom Bryan
N3AJA


On 10/28/2019 10:29 AM, Oz-in-DFW wrote:
I'd still remove and reseat both ends.

Where are you in the world? I have a VGA/serial/GPIB card in my 3014
that we might be able to mate with your scope briefly.






hardyhansendk
 

Hi
I have used - https://www.ccflwarehouse.com/
replacing in e4406A --just shipped the old ones and they made the replacement the right size.
Hardy

-----Oprindelig meddelelse-----
Fra: TekScopes@groups.io [mailto:TekScopes@groups.io] På vegne af Harvey White
Sendt: 6. november 2019 16:59
Til: TekScopes@groups.io
Emne: Re: [TekScopes] TDS3044B repair

This is the first item that came up when searching for CCFL LED replacements

https://www.ccflwarehouse.com/

no idea if they have anything that will fit.

I have made CCFL replacement strips for some odd displays, the older
Optrex DSTN color displays and the FG0800 8 inch VGA display.

Due to the lack of 12 volts in a battery operated project, all of them
are designed to run the LEDS in parallel, at about 15 ma per led, about
9 per 4 inch strip. The strips are designed to be stacked, resulting in
parallel operation.

Whether or not the lamps can be reasonably replaced depends on the
manufacturer. In the Optrex displays, remove a screw, swing a shield
aside, and pull out the tube. In the FG0800, it's more involved (and
takes 4 strips), even more if you wanted the side. The silly tube is a
top, left, and bottom assembly.

The replacement should be made to run off the (suspect 12 volts) supply,
and a simple PWM would easily replace the inverter. I'm sure it varies
wildly.

I know there's a market out there, and the more common the display,
perhaps the easier it is to find the LED replacement, or even the tube
itself (which I'd recommend unless you want to go LED).

I went LED because the power consumption in battery operated equipment
goes down by 50 to 75%, and I'm not happy with 1600 volts running around
an experimental setup.

So give these people a try, they seem to be going laptop, so no idea
what else they do.


You might also want to look here:

https://www.plazmo.com/collections/raw-ccfl-lamps/products/ccfl-backlight-for-tds3000-oscilloscope

10 dollars.

Harvey


On 11/6/2019 10:03 AM, David Kuhn wrote:
" there are commercially
available LED backlight kits to replace the CCFL lamps. "

I would be in your dept if you could point me to an LED replacement for the
fluorescent tubes in the NEC displays like that are used in the TDS3000
series (no bloody A, No bloody B or C). I'll get the actual NEC LCD part
number and reply again later. I wonder if the LED replacement is made to
run off the fluorescent tube inverter supply? I ask that because that
supply has software control line to control the brightness. LET is
probably off or on, unless it is designed to run off the inverter or a
software equivalent inverter is available (retrofitting old equipment not
designing new stuff).

dave

On Tue, Nov 5, 2019 at 2:31 PM Harvey White <madyn@...> wrote:

On 11/5/2019 1:59 PM, David Kuhn wrote:
Sorry for the response delay.

I am in Lewistown, PA. How cheap are the displays and where are you
finding them? I have found the ones, used in the Ultrasonic instruments
I
mentioned, on Alliexpress, and EBAY (haven't ordered any from either
one),
but I can not find the backlight tubes, which I find is usually the
problem
with the displays. The displays may be just slightly different than in
the
TDS3032, but if so, only mechanically. The connectors are the same, and
I
really think the part numbers are the same. It's not a real easy
replacement in those TDS scopes. It looks easy, but it's a pain in the
butt.
Depending on the manufacturer of the display, there are commercially
available LED backlight kits to replace the CCFL lamps.
You may want to buy the TDS3GV on EBAY. I can't use a TDS3032 without
one,
but I have written a lot of service software in VBA and VB6 that
automatically sets up the scopes and gets data from them. I can also
project my TDS3032 to the 32" TV mounted on the wall above it (an older
Sceptre with VGA input) and that's pretty cool.

Again, if the cables are seated well, I doubt the LCD is bad with an
all-white display. My thoughts are a main PCB issue. A TSD3GV could
prove
me wrong.
If you find an all white display, then depending on the type of display
(positive or negative) you'd suspect no signals to it, or improper signals.

The display is likely to take either 5 or 3.3 volts, recent ones that I
have take 3.3. Older STN displays can take 5. The white is the result
of the backlight working, but no active pixels at all (hence no
polarization, etc....).

Like a CRT display, you'll be looking for a horizontal sync (at perhaps
30 Khz), vertical sync (say 60 or so Hz), a DE (likely at horizontal
rate and active high), and a pixel clock at about 25 or so Mhz. You'd
also expect supply voltages to be somewhere on the display. If the
timing is right and the voltages are there, then the display ought to be
showing something. If not, then look at the other pins, they should be
R,G,B digital signals, either in 565 (for a 16 bit panel) or 666 (for an
18 bit panel). If there's any activity on them, then with the right
sync signals, they ought to be giving something on the display.

Harvey



Dave

On Tue, Oct 29, 2019 at 10:55 PM Tom B <tbryan@...> wrote:

Hi Dave,

I tried the "B Trig" and nothing happened. Displays are fairly cheap
but I don't want to buy one unless I have to.

Thank you for the offer. I would be a long while before I make it up
that way.

What town are you in?

Tom

On 10/29/2019 4:52 PM, David Kuhn wrote:
I'm in central, PA, about 3 hours from you if you ever want to come up
and
try it here with one of my VGA/GPIB modules.

Before that. Power it up while holding in the "B TRIG" button (might
be
different on the TDS3014), which on my TDS3032's causes a RESET. I've
had
that fix display issues after replacing the battery NVRAM in in the
scope.
The display in the TDS3032, is the exact same LCD used in the GEIT
Phasor
XS and USN60 instruments. I have worked on many. I have never seen
the
LCD fail on those instrument where it's all white. Typical, if not
broken,
is smeary displays that lines seems to go out of sync. Dim, of course
with
broken backlight tubes.

Dave

On Mon, Oct 28, 2019 at 10:50 PM Tom B <tbryan@...> wrote:

Hi Rich (?),

Thanks. I am located in Maryland near Washington DC.

If anyone in the Washington DC area has a TDS3GV that I could come
over
and quickly test my scope with, I would appreciate it.

Tom Bryan
N3AJA


On 10/28/2019 10:29 AM, Oz-in-DFW wrote:
I'd still remove and reseat both ends.

Where are you in the world? I have a VGA/serial/GPIB card in my 3014
that we might be able to mate with your scope briefly.









--
Denne mail er kontrolleret for vira af AVG.
http://www.avg.com


Mark Litwack
 

I have a TDS3054 I bought new 20 years ago and I never noticed how dim the display had become over the years. I was able to replace the CCFL tubes with new ones and it made a huge difference in readability.

You can replace the CCFL tubes as slide-out FRUs, NEC part #65LHS–3L Or, solder in bare CCFLs. I did the latter with tubes from ccflwarehouse.com, part #CC26153. You will need two tubes. The TDS3xxx "B" version uses the same CCFLs according to the Tek service manual.


Tom B
 

Hello All,

I am just catching up on this thread.

There is a youtube video on replacing the CCFLs with LEDs here https://www.youtube.com/watch?v=iVU0YPIeovM

The part number for the TDS3000 (no letter) display is listed in the service manual as an NEC NL6448AC20–06.  These displays are available on ebay and other places for about $60US.   I think the part number for the B model is NL6448BC20-08, but I am not 100% sure of that.  These displays are running about $80-$100US. The only difference I can find in the in the datasheets between NL6448AC20–06 and the NL6448BC20-08 is that the -08 model has higher luminance.

Can anyone verify the part number on the TDS3000B display?

I will check for the for the signals that Harvey mentioned when I have time.  The pins that go to the display are really hard to get to because of the way this thing is built.   There are the test points on the main board, but the service manual makes no mention of what they are for.

Tom Bryan
N3AJA

On 11/6/2019 10:58 AM, Harvey White wrote:
This is the first item that came up when searching for CCFL LED replacements

https://urldefense.com/v3/__https://www.ccflwarehouse.com/__;!b9GWhakWANQ!1VZO1N_UzGPrK5tvZk-sSIE3W2ulp1zapXqXmDScqYhd9jWmbO6SGjvZhNdA$
no idea if they have anything that will fit.

I have made CCFL replacement strips for some odd displays, the older Optrex DSTN color displays and the FG0800 8 inch VGA display.

Due to the lack of 12 volts in a battery operated project, all of them are designed to run the LEDS in parallel, at about 15 ma per led, about 9 per 4 inch strip.  The strips are designed to be stacked, resulting in parallel operation.

Whether or not the lamps can be reasonably replaced depends on the manufacturer.  In the Optrex displays, remove a screw, swing a shield aside, and pull out the tube.  In the FG0800, it's more involved (and takes 4 strips), even more if you wanted the side. The silly tube is a top, left, and bottom assembly.

The replacement should be made to run off the (suspect 12 volts) supply, and a simple PWM would easily replace the inverter.  I'm sure it varies wildly.

I know there's a market out there, and the more common the display, perhaps the easier it is to find the LED replacement,  or even the tube itself (which I'd recommend unless you want to go LED).

I went LED because the power consumption in battery operated equipment goes down by 50 to 75%, and I'm not happy with 1600 volts running around an experimental setup.

So give these people a try, they seem to be going laptop, so no idea what else they do.


You might also want to look here:

https://urldefense.com/v3/__https://www.plazmo.com/collections/raw-ccfl-lamps/products/ccfl-backlight-for-tds3000-oscilloscope__;!b9GWhakWANQ!1VZO1N_UzGPrK5tvZk-sSIE3W2ulp1zapXqXmDScqYhd9jWmbO6SGtNxwsuf$
10 dollars.

Harvey


On 11/6/2019 10:03 AM, David Kuhn wrote:
" there are commercially
available LED backlight kits to replace the CCFL lamps.  "

I would be in your dept if you could point me to an LED replacement for the
fluorescent tubes in the NEC displays like that are used in the TDS3000
series (no bloody A, No bloody B or C).  I'll get the actual NEC LCD part
number and reply again later.  I wonder if the LED replacement is made to
run off the fluorescent tube inverter supply?  I ask that because that
supply has software control line to control the brightness.  LET is
probably off or on, unless it is designed to run off the inverter or a
software equivalent inverter is available (retrofitting old equipment not
designing new stuff).

dave

On Tue, Nov 5, 2019 at 2:31 PM Harvey White <madyn@...> wrote:

On 11/5/2019 1:59 PM, David Kuhn wrote:
Sorry for the response delay.

I am in Lewistown, PA.  How cheap are the displays and where are you
finding them?  I have found the ones, used in the Ultrasonic instruments
I
mentioned, on Alliexpress, and EBAY (haven't ordered any from either
one),
but I can not find the backlight tubes, which I find is usually the
problem
with the displays.  The displays may be just slightly different than in
the
TDS3032, but if so, only mechanically.  The connectors are the same, and
I
really think the part numbers are the same.  It's not a real easy
replacement in those TDS scopes.  It looks easy, but it's a pain in the
butt.
Depending on the manufacturer of the display, there are commercially
available LED backlight kits to replace the CCFL lamps.
You may want to buy the TDS3GV on EBAY.  I can't use a TDS3032 without
one,
but I have written a lot of service software in VBA and VB6 that
automatically sets up the scopes and gets data from them.  I can also
project my TDS3032 to the 32" TV mounted on the wall above it (an older
Sceptre with VGA input) and that's pretty cool.

Again, if the cables are seated well, I doubt the LCD is bad with an
all-white display.  My thoughts are a main PCB issue. A TSD3GV could
prove
me wrong.
If you find an all white display, then depending on the type of display
(positive or negative) you'd suspect no signals to it, or improper signals.

The display is likely to take either 5 or 3.3 volts, recent ones that I
have take 3.3.  Older STN displays can take 5.  The white is the result
of the backlight working, but no active pixels at all (hence no
polarization, etc....).

Like a CRT display, you'll be looking for a horizontal sync (at perhaps
30 Khz), vertical sync (say 60 or so Hz), a DE (likely at horizontal
rate and active high), and a pixel clock at about 25 or so Mhz.  You'd
also expect supply voltages to be somewhere on the display. If the
timing is right and the voltages are there, then the display ought to be
showing something.  If not, then look at the other pins, they should be
R,G,B digital signals, either in 565 (for a 16 bit panel) or 666 (for an
18 bit panel).  If there's any activity on them, then with the right
sync signals, they ought to be giving something on the display.

Harvey



Dave

On Tue, Oct 29, 2019 at 10:55 PM Tom B <tbryan@...> wrote:

Hi Dave,

I  tried the "B Trig" and nothing happened.  Displays are fairly cheap
but I don't want to buy one unless I have to.

Thank you for the offer.  I would be a long while before I make it up
that way.

What town are you in?

Tom

On 10/29/2019 4:52 PM, David Kuhn wrote:
I'm in central, PA, about 3 hours from you if you ever want to come up
and
try it here with one of my VGA/GPIB modules.

Before that.  Power it up while holding in the "B TRIG" button (might
be
different on the TDS3014), which on my TDS3032's causes a RESET.  I've
had
that fix display issues after replacing the battery NVRAM in in the
scope.
The display in the TDS3032, is the exact same LCD used in the GEIT
Phasor
XS and USN60 instruments.  I have worked on many.  I have never seen
the
LCD fail on those instrument where it's all white.  Typical, if not
broken,
is smeary displays that lines seems to go out of sync.  Dim, of course
with
broken backlight tubes.

Dave

On Mon, Oct 28, 2019 at 10:50 PM Tom B <tbryan@...> wrote:

Hi Rich (?),

Thanks. I am located in Maryland near Washington DC.

If anyone in the Washington DC area has a TDS3GV that I could come
over
and quickly test my scope with, I would appreciate it.

Tom Bryan
N3AJA


On 10/28/2019 10:29 AM, Oz-in-DFW wrote:
I'd still remove and reseat both ends.

Where are you in the world?  I have a VGA/serial/GPIB card in my 3014
that we might be able to mate with your scope briefly.








Harvey White
 

If you have some familiarity with LCD displays, or CRT displays with separate drive, then *if* the signals are good, you should be able to recognize them.  If they're bad, however, well.... Let alone which test point is what......

Harvey

On 11/6/2019 10:08 PM, Tom B wrote:
Hello All,

I am just catching up on this thread.

There is a youtube video on replacing the CCFLs with LEDs here https://www.youtube.com/watch?v=iVU0YPIeovM

The part number for the TDS3000 (no letter) display is listed in the service manual as an NEC NL6448AC20–06.  These displays are available on ebay and other places for about $60US.   I think the part number for the B model is NL6448BC20-08, but I am not 100% sure of that.  These displays are running about $80-$100US. The only difference I can find in the in the datasheets between NL6448AC20–06 and the NL6448BC20-08 is that the -08 model has higher luminance.

Can anyone verify the part number on the TDS3000B display?

I will check for the for the signals that Harvey mentioned when I have time.  The pins that go to the display are really hard to get to because of the way this thing is built.   There are the test points on the main board, but the service manual makes no mention of what they are for.

Tom Bryan
N3AJA


On 11/6/2019 10:58 AM, Harvey White wrote:
This is the first item that came up when searching for CCFL LED replacements

https://urldefense.com/v3/__https://www.ccflwarehouse.com/__;!b9GWhakWANQ!1VZO1N_UzGPrK5tvZk-sSIE3W2ulp1zapXqXmDScqYhd9jWmbO6SGjvZhNdA$
no idea if they have anything that will fit.

I have made CCFL replacement strips for some odd displays, the older Optrex DSTN color displays and the FG0800 8 inch VGA display.

Due to the lack of 12 volts in a battery operated project, all of them are designed to run the LEDS in parallel, at about 15 ma per led, about 9 per 4 inch strip.  The strips are designed to be stacked, resulting in parallel operation.

Whether or not the lamps can be reasonably replaced depends on the manufacturer.  In the Optrex displays, remove a screw, swing a shield aside, and pull out the tube.  In the FG0800, it's more involved (and takes 4 strips), even more if you wanted the side. The silly tube is a top, left, and bottom assembly.

The replacement should be made to run off the (suspect 12 volts) supply, and a simple PWM would easily replace the inverter.  I'm sure it varies wildly.

I know there's a market out there, and the more common the display, perhaps the easier it is to find the LED replacement, or even the tube itself (which I'd recommend unless you want to go LED).

I went LED because the power consumption in battery operated equipment goes down by 50 to 75%, and I'm not happy with 1600 volts running around an experimental setup.

So give these people a try, they seem to be going laptop, so no idea what else they do.


You might also want to look here:

https://urldefense.com/v3/__https://www.plazmo.com/collections/raw-ccfl-lamps/products/ccfl-backlight-for-tds3000-oscilloscope__;!b9GWhakWANQ!1VZO1N_UzGPrK5tvZk-sSIE3W2ulp1zapXqXmDScqYhd9jWmbO6SGtNxwsuf$
10 dollars.

Harvey


On 11/6/2019 10:03 AM, David Kuhn wrote:
" there are commercially
available LED backlight kits to replace the CCFL lamps.  "

I would be in your dept if you could point me to an LED replacement for the
fluorescent tubes in the NEC displays like that are used in the TDS3000
series (no bloody A, No bloody B or C).  I'll get the actual NEC LCD part
number and reply again later.  I wonder if the LED replacement is made to
run off the fluorescent tube inverter supply?  I ask that because that
supply has software control line to control the brightness. LET is
probably off or on, unless it is designed to run off the inverter or a
software equivalent inverter is available (retrofitting old equipment not
designing new stuff).

dave

On Tue, Nov 5, 2019 at 2:31 PM Harvey White <madyn@...> wrote:

On 11/5/2019 1:59 PM, David Kuhn wrote:
Sorry for the response delay.

I am in Lewistown, PA.  How cheap are the displays and where are you
finding them?  I have found the ones, used in the Ultrasonic instruments
I
mentioned, on Alliexpress, and EBAY (haven't ordered any from either
one),
but I can not find the backlight tubes, which I find is usually the
problem
with the displays.  The displays may be just slightly different than in
the
TDS3032, but if so, only mechanically.  The connectors are the same, and
I
really think the part numbers are the same.  It's not a real easy
replacement in those TDS scopes.  It looks easy, but it's a pain in the
butt.
Depending on the manufacturer of the display, there are commercially
available LED backlight kits to replace the CCFL lamps.
You may want to buy the TDS3GV on EBAY.  I can't use a TDS3032 without
one,
but I have written a lot of service software in VBA and VB6 that
automatically sets up the scopes and gets data from them. I can also
project my TDS3032 to the 32" TV mounted on the wall above it (an older
Sceptre with VGA input) and that's pretty cool.

Again, if the cables are seated well, I doubt the LCD is bad with an
all-white display.  My thoughts are a main PCB issue. A TSD3GV could
prove
me wrong.
If you find an all white display, then depending on the type of display
(positive or negative) you'd suspect no signals to it, or improper signals.

The display is likely to take either 5 or 3.3 volts, recent ones that I
have take 3.3.  Older STN displays can take 5.  The white is the result
of the backlight working, but no active pixels at all (hence no
polarization, etc....).

Like a CRT display, you'll be looking for a horizontal sync (at perhaps
30 Khz), vertical sync (say 60 or so Hz), a DE (likely at horizontal
rate and active high), and a pixel clock at about 25 or so Mhz.  You'd
also expect supply voltages to be somewhere on the display. If the
timing is right and the voltages are there, then the display ought to be
showing something.  If not, then look at the other pins, they should be
R,G,B digital signals, either in 565 (for a 16 bit panel) or 666 (for an
18 bit panel).  If there's any activity on them, then with the right
sync signals, they ought to be giving something on the display.

Harvey



Dave

On Tue, Oct 29, 2019 at 10:55 PM Tom B <tbryan@...> wrote:

Hi Dave,

I  tried the "B Trig" and nothing happened.  Displays are fairly cheap
but I don't want to buy one unless I have to.

Thank you for the offer.  I would be a long while before I make it up
that way.

What town are you in?

Tom

On 10/29/2019 4:52 PM, David Kuhn wrote:
I'm in central, PA, about 3 hours from you if you ever want to come up
and
try it here with one of my VGA/GPIB modules.

Before that.  Power it up while holding in the "B TRIG" button (might
be
different on the TDS3014), which on my TDS3032's causes a RESET.  I've
had
that fix display issues after replacing the battery NVRAM in in the
scope.
The display in the TDS3032, is the exact same LCD used in the GEIT
Phasor
XS and USN60 instruments.  I have worked on many.  I have never seen
the
LCD fail on those instrument where it's all white.  Typical, if not
broken,
is smeary displays that lines seems to go out of sync.  Dim, of course
with
broken backlight tubes.

Dave

On Mon, Oct 28, 2019 at 10:50 PM Tom B <tbryan@...> wrote:

Hi Rich (?),

Thanks. I am located in Maryland near Washington DC.

If anyone in the Washington DC area has a TDS3GV that I could come
over
and quickly test my scope with, I would appreciate it.

Tom Bryan
N3AJA


On 10/28/2019 10:29 AM, Oz-in-DFW wrote:
I'd still remove and reseat both ends.

Where are you in the world?  I have a VGA/serial/GPIB card in my 3014
that we might be able to mate with your scope briefly.











David Kuhn
 

https://www.youtube.com/watch?time_continue=261&v=iVU0YPIeovM

http://lcdparts.net/UBDetail.aspx?ProductID=3796

Looks like a perfect solution for the NEC on the TDS3000 series and in the
NEC 65BLM05 Display (virtually the same display as the one TEK uses) in the
instruments I do a lot of work on.

Unlike the video, I would not remove the paper exposing the glue when
installing the strips. I don't want those LED strips permanently in my
LCDs in case they fail.

Dave

On Wed, Nov 6, 2019 at 11:40 PM Harvey White <madyn@...> wrote:

If you have some familiarity with LCD displays, or CRT displays with
separate drive, then *if* the signals are good, you should be able to
recognize them. If they're bad, however, well.... Let alone which test
point is what......

Harvey


On 11/6/2019 10:08 PM, Tom B wrote:
Hello All,

I am just catching up on this thread.

There is a youtube video on replacing the CCFLs with LEDs here
https://www.youtube.com/watch?v=iVU0YPIeovM

The part number for the TDS3000 (no letter) display is listed in the
service manual as an NEC NL6448AC20–06. These displays are available
on ebay and other places for about $60US. I think the part number
for the B model is NL6448BC20-08, but I am not 100% sure of that.
These displays are running about $80-$100US. The only difference I can
find in the in the datasheets between NL6448AC20–06 and the
NL6448BC20-08 is that the -08 model has higher luminance.

Can anyone verify the part number on the TDS3000B display?

I will check for the for the signals that Harvey mentioned when I have
time. The pins that go to the display are really hard to get to
because of the way this thing is built. There are the test points on
the main board, but the service manual makes no mention of what they
are for.

Tom Bryan
N3AJA


On 11/6/2019 10:58 AM, Harvey White wrote:
This is the first item that came up when searching for CCFL LED
replacements

https://urldefense.com/v3/__https://www.ccflwarehouse.com/__;!b9GWhakWANQ!1VZO1N_UzGPrK5tvZk-sSIE3W2ulp1zapXqXmDScqYhd9jWmbO6SGjvZhNdA$

no idea if they have anything that will fit.

I have made CCFL replacement strips for some odd displays, the older
Optrex DSTN color displays and the FG0800 8 inch VGA display.

Due to the lack of 12 volts in a battery operated project, all of
them are designed to run the LEDS in parallel, at about 15 ma per
led, about 9 per 4 inch strip. The strips are designed to be
stacked, resulting in parallel operation.

Whether or not the lamps can be reasonably replaced depends on the
manufacturer. In the Optrex displays, remove a screw, swing a shield
aside, and pull out the tube. In the FG0800, it's more involved (and
takes 4 strips), even more if you wanted the side. The silly tube is
a top, left, and bottom assembly.

The replacement should be made to run off the (suspect 12 volts)
supply, and a simple PWM would easily replace the inverter. I'm sure
it varies wildly.

I know there's a market out there, and the more common the display,
perhaps the easier it is to find the LED replacement, or even the
tube itself (which I'd recommend unless you want to go LED).

I went LED because the power consumption in battery operated
equipment goes down by 50 to 75%, and I'm not happy with 1600 volts
running around an experimental setup.

So give these people a try, they seem to be going laptop, so no idea
what else they do.


You might also want to look here:

https://urldefense.com/v3/__https://www.plazmo.com/collections/raw-ccfl-lamps/products/ccfl-backlight-for-tds3000-oscilloscope__;!b9GWhakWANQ!1VZO1N_UzGPrK5tvZk-sSIE3W2ulp1zapXqXmDScqYhd9jWmbO6SGtNxwsuf$

10 dollars.

Harvey


On 11/6/2019 10:03 AM, David Kuhn wrote:
" there are commercially
available LED backlight kits to replace the CCFL lamps. "

I would be in your dept if you could point me to an LED replacement
for the
fluorescent tubes in the NEC displays like that are used in the TDS3000
series (no bloody A, No bloody B or C). I'll get the actual NEC LCD
part
number and reply again later. I wonder if the LED replacement is
made to
run off the fluorescent tube inverter supply? I ask that because that
supply has software control line to control the brightness. LET is
probably off or on, unless it is designed to run off the inverter or a
software equivalent inverter is available (retrofitting old
equipment not
designing new stuff).

dave

On Tue, Nov 5, 2019 at 2:31 PM Harvey White <madyn@...>
wrote:

On 11/5/2019 1:59 PM, David Kuhn wrote:
Sorry for the response delay.

I am in Lewistown, PA. How cheap are the displays and where are you
finding them? I have found the ones, used in the Ultrasonic
instruments
I
mentioned, on Alliexpress, and EBAY (haven't ordered any from either
one),
but I can not find the backlight tubes, which I find is usually the
problem
with the displays. The displays may be just slightly different
than in
the
TDS3032, but if so, only mechanically. The connectors are the
same, and
I
really think the part numbers are the same. It's not a real easy
replacement in those TDS scopes. It looks easy, but it's a pain
in the
butt.
Depending on the manufacturer of the display, there are commercially
available LED backlight kits to replace the CCFL lamps.
You may want to buy the TDS3GV on EBAY. I can't use a TDS3032
without
one,
but I have written a lot of service software in VBA and VB6 that
automatically sets up the scopes and gets data from them. I can also
project my TDS3032 to the 32" TV mounted on the wall above it (an
older
Sceptre with VGA input) and that's pretty cool.

Again, if the cables are seated well, I doubt the LCD is bad with an
all-white display. My thoughts are a main PCB issue. A TSD3GV could
prove
me wrong.
If you find an all white display, then depending on the type of
display
(positive or negative) you'd suspect no signals to it, or improper
signals.

The display is likely to take either 5 or 3.3 volts, recent ones
that I
have take 3.3. Older STN displays can take 5. The white is the
result
of the backlight working, but no active pixels at all (hence no
polarization, etc....).

Like a CRT display, you'll be looking for a horizontal sync (at
perhaps
30 Khz), vertical sync (say 60 or so Hz), a DE (likely at horizontal
rate and active high), and a pixel clock at about 25 or so Mhz. You'd
also expect supply voltages to be somewhere on the display. If the
timing is right and the voltages are there, then the display ought
to be
showing something. If not, then look at the other pins, they
should be
R,G,B digital signals, either in 565 (for a 16 bit panel) or 666
(for an
18 bit panel). If there's any activity on them, then with the right
sync signals, they ought to be giving something on the display.

Harvey



Dave

On Tue, Oct 29, 2019 at 10:55 PM Tom B <tbryan@...> wrote:

Hi Dave,

I tried the "B Trig" and nothing happened. Displays are fairly
cheap
but I don't want to buy one unless I have to.

Thank you for the offer. I would be a long while before I make
it up
that way.

What town are you in?

Tom

On 10/29/2019 4:52 PM, David Kuhn wrote:
I'm in central, PA, about 3 hours from you if you ever want to
come up
and
try it here with one of my VGA/GPIB modules.

Before that. Power it up while holding in the "B TRIG" button
(might
be
different on the TDS3014), which on my TDS3032's causes a
RESET. I've
had
that fix display issues after replacing the battery NVRAM in in the
scope.
The display in the TDS3032, is the exact same LCD used in the GEIT
Phasor
XS and USN60 instruments. I have worked on many. I have never
seen
the
LCD fail on those instrument where it's all white. Typical, if not
broken,
is smeary displays that lines seems to go out of sync. Dim, of
course
with
broken backlight tubes.

Dave

On Mon, Oct 28, 2019 at 10:50 PM Tom B <tbryan@...> wrote:

Hi Rich (?),

Thanks. I am located in Maryland near Washington DC.

If anyone in the Washington DC area has a TDS3GV that I could come
over
and quickly test my scope with, I would appreciate it.

Tom Bryan
N3AJA


On 10/28/2019 10:29 AM, Oz-in-DFW wrote:
I'd still remove and reseat both ends.

Where are you in the world? I have a VGA/serial/GPIB card in
my 3014
that we might be able to mate with your scope briefly.














Tom B
 

Hi Dave,

If you look at this video https://www.youtube.com/watch?v=Z_gvjmKHN4Y it shows a part number on the back of the display as 65BLM04 and on the front of the display the tag says NL6448BC20-08.  If you search each of these part numbers on ebay, the price is very different when they are actually the same part.   The cheapest price I could find for the 65BLM05 is $158.74 (used), while the cheapest price for the NL6448BC20-08 is $88 for a new part.   These appear to be exactly the same part.  Any idea if there is any difference?

Tom

On 11/7/2019 2:28 PM, David Kuhn wrote:
https://urldefense.com/v3/__https://www.youtube.com/watch?time_continue=261&v=iVU0YPIeovM__;!b9GWhakWANQ!wbXzExaWmEY10yA6ddr1j7dzMVPNV7j4iMLI9u6paEFuQ5tXhS6mqOV8S_HN$

https://urldefense.com/v3/__http://lcdparts.net/UBDetail.aspx?ProductID=3796__;!b9GWhakWANQ!wbXzExaWmEY10yA6ddr1j7dzMVPNV7j4iMLI9u6paEFuQ5tXhS6mqCtAAjYv$

Looks like a perfect solution for the NEC on the TDS3000 series and in the
NEC 65BLM05 Display (virtually the same display as the one TEK uses) in the
instruments I do a lot of work on.

Unlike the video, I would not remove the paper exposing the glue when
installing the strips. I don't want those LED strips permanently in my
LCDs in case they fail.

Dave

On Wed, Nov 6, 2019 at 11:40 PM Harvey White <madyn@...> wrote:

If you have some familiarity with LCD displays, or CRT displays with
separate drive, then *if* the signals are good, you should be able to
recognize them. If they're bad, however, well.... Let alone which test
point is what......

Harvey


On 11/6/2019 10:08 PM, Tom B wrote:
Hello All,

I am just catching up on this thread.

There is a youtube video on replacing the CCFLs with LEDs here
https://urldefense.com/v3/__https://www.youtube.com/watch?v=iVU0YPIeovM__;!b9GWhakWANQ!wbXzExaWmEY10yA6ddr1j7dzMVPNV7j4iMLI9u6paEFuQ5tXhS6mqLLaLTRs$

The part number for the TDS3000 (no letter) display is listed in the
service manual as an NEC NL6448AC20–06. These displays are available
on ebay and other places for about $60US. I think the part number
for the B model is NL6448BC20-08, but I am not 100% sure of that.
These displays are running about $80-$100US. The only difference I can
find in the in the datasheets between NL6448AC20–06 and the
NL6448BC20-08 is that the -08 model has higher luminance.

Can anyone verify the part number on the TDS3000B display?

I will check for the for the signals that Harvey mentioned when I have
time. The pins that go to the display are really hard to get to
because of the way this thing is built. There are the test points on
the main board, but the service manual makes no mention of what they
are for.

Tom Bryan
N3AJA


On 11/6/2019 10:58 AM, Harvey White wrote:
This is the first item that came up when searching for CCFL LED
replacements

https://urldefense.com/v3/__https://www.ccflwarehouse.com/__;!b9GWhakWANQ!1VZO1N_UzGPrK5tvZk-sSIE3W2ulp1zapXqXmDScqYhd9jWmbO6SGjvZhNdA$
no idea if they have anything that will fit.

I have made CCFL replacement strips for some odd displays, the older
Optrex DSTN color displays and the FG0800 8 inch VGA display.

Due to the lack of 12 volts in a battery operated project, all of
them are designed to run the LEDS in parallel, at about 15 ma per
led, about 9 per 4 inch strip. The strips are designed to be
stacked, resulting in parallel operation.

Whether or not the lamps can be reasonably replaced depends on the
manufacturer. In the Optrex displays, remove a screw, swing a shield
aside, and pull out the tube. In the FG0800, it's more involved (and
takes 4 strips), even more if you wanted the side. The silly tube is
a top, left, and bottom assembly.

The replacement should be made to run off the (suspect 12 volts)
supply, and a simple PWM would easily replace the inverter. I'm sure
it varies wildly.

I know there's a market out there, and the more common the display,
perhaps the easier it is to find the LED replacement, or even the
tube itself (which I'd recommend unless you want to go LED).

I went LED because the power consumption in battery operated
equipment goes down by 50 to 75%, and I'm not happy with 1600 volts
running around an experimental setup.

So give these people a try, they seem to be going laptop, so no idea
what else they do.


You might also want to look here:

https://urldefense.com/v3/__https://www.plazmo.com/collections/raw-ccfl-lamps/products/ccfl-backlight-for-tds3000-oscilloscope__;!b9GWhakWANQ!1VZO1N_UzGPrK5tvZk-sSIE3W2ulp1zapXqXmDScqYhd9jWmbO6SGtNxwsuf$
10 dollars.

Harvey


On 11/6/2019 10:03 AM, David Kuhn wrote:
" there are commercially
available LED backlight kits to replace the CCFL lamps. "

I would be in your dept if you could point me to an LED replacement
for the
fluorescent tubes in the NEC displays like that are used in the TDS3000
series (no bloody A, No bloody B or C). I'll get the actual NEC LCD
part
number and reply again later. I wonder if the LED replacement is
made to
run off the fluorescent tube inverter supply? I ask that because that
supply has software control line to control the brightness. LET is
probably off or on, unless it is designed to run off the inverter or a
software equivalent inverter is available (retrofitting old
equipment not
designing new stuff).

dave

On Tue, Nov 5, 2019 at 2:31 PM Harvey White <madyn@...>
wrote:

On 11/5/2019 1:59 PM, David Kuhn wrote:
Sorry for the response delay.

I am in Lewistown, PA. How cheap are the displays and where are you
finding them? I have found the ones, used in the Ultrasonic
instruments
I
mentioned, on Alliexpress, and EBAY (haven't ordered any from either
one),
but I can not find the backlight tubes, which I find is usually the
problem
with the displays. The displays may be just slightly different
than in
the
TDS3032, but if so, only mechanically. The connectors are the
same, and
I
really think the part numbers are the same. It's not a real easy
replacement in those TDS scopes. It looks easy, but it's a pain
in the
butt.
Depending on the manufacturer of the display, there are commercially
available LED backlight kits to replace the CCFL lamps.
You may want to buy the TDS3GV on EBAY. I can't use a TDS3032
without
one,
but I have written a lot of service software in VBA and VB6 that
automatically sets up the scopes and gets data from them. I can also
project my TDS3032 to the 32" TV mounted on the wall above it (an
older
Sceptre with VGA input) and that's pretty cool.

Again, if the cables are seated well, I doubt the LCD is bad with an
all-white display. My thoughts are a main PCB issue. A TSD3GV could
prove
me wrong.
If you find an all white display, then depending on the type of
display
(positive or negative) you'd suspect no signals to it, or improper
signals.

The display is likely to take either 5 or 3.3 volts, recent ones
that I
have take 3.3. Older STN displays can take 5. The white is the
result
of the backlight working, but no active pixels at all (hence no
polarization, etc....).

Like a CRT display, you'll be looking for a horizontal sync (at
perhaps
30 Khz), vertical sync (say 60 or so Hz), a DE (likely at horizontal
rate and active high), and a pixel clock at about 25 or so Mhz. You'd
also expect supply voltages to be somewhere on the display. If the
timing is right and the voltages are there, then the display ought
to be
showing something. If not, then look at the other pins, they
should be
R,G,B digital signals, either in 565 (for a 16 bit panel) or 666
(for an
18 bit panel). If there's any activity on them, then with the right
sync signals, they ought to be giving something on the display.

Harvey



Dave

On Tue, Oct 29, 2019 at 10:55 PM Tom B <tbryan@...> wrote:

Hi Dave,

I tried the "B Trig" and nothing happened. Displays are fairly
cheap
but I don't want to buy one unless I have to.

Thank you for the offer. I would be a long while before I make
it up
that way.

What town are you in?

Tom

On 10/29/2019 4:52 PM, David Kuhn wrote:
I'm in central, PA, about 3 hours from you if you ever want to
come up
and
try it here with one of my VGA/GPIB modules.

Before that. Power it up while holding in the "B TRIG" button
(might
be
different on the TDS3014), which on my TDS3032's causes a
RESET. I've
had
that fix display issues after replacing the battery NVRAM in in the
scope.
The display in the TDS3032, is the exact same LCD used in the GEIT
Phasor
XS and USN60 instruments. I have worked on many. I have never
seen
the
LCD fail on those instrument where it's all white. Typical, if not
broken,
is smeary displays that lines seems to go out of sync. Dim, of
course
with
broken backlight tubes.

Dave

On Mon, Oct 28, 2019 at 10:50 PM Tom B <tbryan@...> wrote:

Hi Rich (?),

Thanks. I am located in Maryland near Washington DC.

If anyone in the Washington DC area has a TDS3GV that I could come
over
and quickly test my scope with, I would appreciate it.

Tom Bryan
N3AJA


On 10/28/2019 10:29 AM, Oz-in-DFW wrote:
I'd still remove and reseat both ends.

Where are you in the world? I have a VGA/serial/GPIB card in
my 3014
that we might be able to mate with your scope briefly.