Date   

Re: TDS3044B repair

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.














Re: Knob repair tips

Dave Brown
 

I turn the diameter of the metal hub down just enough so it fits within the remnants of the knob. They I use epoxy and glue it all together. I only have examples of gears on the vintageTEK website but it works equally well with knobs.
https://vintagetek.org/repairing-knobs/

Dave


human element

John Griessen
 

On 11/7/19 11:38 AM, Nenad Filipovic wrote:
I live on the other side of the globe
So, where *DO* you live, Nenad?

--
John in Texas (moving to New Mexico soon)
R7844, 7603's, 7904A, 7104's, R7903, 7854, 2230
RM564, RM561B, 321A, 310


Re: Upgrading a TDS3BAT

Miguel Work
 

Mine is working with lithium, I have some notes.

Here you can find some information:

https://www.eevblog.com/forum/testgear/tek-ths720a-portable-scope-teardowndiscussion/

Regards

-----Mensaje original-----
De: TekScopes@groups.io [mailto:TekScopes@groups.io] En nombre de Magic_Smoke
Enviado el: jueves, 7 de noviembre de 2019 15:51
Para: TekScopes@groups.io
Asunto: [TekScopes] Upgrading a TDS3BAT

Hello all,

I picked up a tired TDS3BAT (NiCd chemistry, probably containing a failed cell or two) and I was pondering my options for rehabilitation. I will admit I have not even taken the thing apart yet, but in the modern era of batteries we find ourselves I cannot help but think of rewiring it to use lithium cells instead. Does anyone have experience or documentation for these units, and if such a change is practical? I imagine the charging circuit would need replacing, depending on how much of the work happens on the battery side vs. the scope side I am hoping dropping in a dedicated lithium charger will do the trick. Has anyone actually tried this, though? Any pitfalls? Thanks!


Re: I personally don’t think Craig should quit

Nenad Filipovic
 

I live on the other side of the globe and never met any of you, but I
highly appreciate the personal, human element in this group's discussions.
That's what makes friends, and friendship is better than this.
I hope no one quits the group just because we're all - humans.

Nenad.


Re: Tektronix Spectrum Analyzers

Roy Thistle
 

On Mon, Nov 4, 2019 at 11:52 PM, Dennis Tillman W7PF wrote:


One of the experts on the 490 series is our own John Miles who has written
quite a lot of software for various instruments which you can download from
his web site at
http://www.ke5fx.com/gpib/readme.htm
One might also try the following link, for some interesting and well written service notes on 49x SA
http://www.ke5fx.com/49x_notes.pdf
Roy


Re: Upgrading a TDS3BAT

Magic_Smoke
 

Perhaps I should add the goals I have for this project, starting from the highest priority:
1. Not burning down my house
2. Not killing my scope
3. Proper charge readout on the scope
4.Charging while in the scope, but external-only charging is perfectly suitable (and probably safer)

As long as at least the first two goals are met, I am open to suggestions!


Upgrading a TDS3BAT

Magic_Smoke
 

Hello all,

I picked up a tired TDS3BAT (NiCd chemistry, probably containing a failed cell or two) and I was pondering my options for rehabilitation. I will admit I have not even taken the thing apart yet, but in the modern era of batteries we find ourselves I cannot help but think of rewiring it to use lithium cells instead. Does anyone have experience or documentation for these units, and if such a change is practical? I imagine the charging circuit would need replacing, depending on how much of the work happens on the battery side vs. the scope side I am hoping dropping in a dedicated lithium charger will do the trick. Has anyone actually tried this, though? Any pitfalls? Thanks!


Re: A few pics from a new-to-me exhibit in the National Museum of Nuclear Science and History

Daniel Koller
 

I'm no nuclear science history expert, but wrt the original post,  that 535 seems out of place.  The criticality experiments were generally carried out in the 1940's and the 5 series was not available till the 1950's.  Afterall, by 1945 they knew what it took to make a pile of uranium go off.
But in the 1950's the techniques of Nuclear spectroscopy were being developed and that scope would have been at home reading the pulse outputs of scintilation counters.  I used such scopes in Columbia University's undergraduate physics labs in the 1980's for just such pulse counting.   they had not updated the labs in 30 years (!!) so it was very much like working in the 1950s
Someone correct me if I am wrong in my time estimates.
Dan

On Wednesday, November 6, 2019, 10:02:59 PM EST, <sdturne@q.com> wrote:

On Sat, Nov  2, 2019 at 01:10 AM, battyhugh wrote:


If you are in Minneapolis - on the S side of the bridge across the river on
the W side (if I remember correctly) - there is another relic - you have to
decend about 6 stories down - there are masses of HB spec analysers and a
rather large Van de Graffe generator - - very strange (I saw it in early 90's)
- A Dr Weiblen was working at that time on using high voltage pulses to bust
up moon rock. It would be rather interesting to document the remaining
residues of the 50's and 60's (on the marshes near Palo Alto is an old radio
transmission facility - might be interesting... but wait.. there's more!
Hmmm, is it an abandoned site or is someone taking care of it?


Re: I personally don’t think Craig should quit

Lawrance A. Schneider
 

I’m an old man. As a boy, I valued the knowledge base that they had acquired; I actively sought out elderly people for that reason. As an old man, I still value that knowledge base.

I hope you do not quit! As an old man, I understand the challenges age brings about. If you feel you cannot keep up, I understand.

Still, I hope you do not quit.

larry'


Re: Knob repair tips

Dave Voorhis
 

Excellent, thanks! That’s what I'd vaguely remembered.

On 7 Nov 2019, at 12:57, Chuck Harris <cfharris@...> wrote:

I wouldn't, as you really have to be gentle here.

Even the elastic bands, if too tight, will leave
a depression when the knob is in the molten state.

You want the bands stretched a bit, but not even
close to tight.

You should have some compressed air to cool the center
on hand, as the hub can retain heat a lot longer than
you might think. A water dunk would be ok, if the
set screw is removed afterwards, and the knob let to
dry thoroughly.

-Chuck Harris

Tim Phillips wrote:
from Tim P (UK)
................ or use an adjustable hose-clamp ('Jubilee clip') to hold
the bits onto the hub ?

Tim




On Thu, 7 Nov 2019 at 12:36, Chuck Harris <cfharris@...> wrote:

Because the plastic has shrunk, you need to increase
the space for the center hub. The easiest way I have
found is to assemble the parts as well as you can, and
then wrap some rubber bands around the knob to provide
tension.

Then take a soldering iron, and heat the center hub.

The instant the plastic relaxes, remove the heat, and
cool the hub by blowing on it.

After all is done, a drop of acrylic solvent glue will,
seal the deal, so to speak.

-Chuck Harris


Re: Knob repair tips

Chuck Harris
 

I wouldn't, as you really have to be gentle here.

Even the elastic bands, if too tight, will leave
a depression when the knob is in the molten state.

You want the bands stretched a bit, but not even
close to tight.

You should have some compressed air to cool the center
on hand, as the hub can retain heat a lot longer than
you might think. A water dunk would be ok, if the
set screw is removed afterwards, and the knob let to
dry thoroughly.

-Chuck Harris

Tim Phillips wrote:

from Tim P (UK)
................ or use an adjustable hose-clamp ('Jubilee clip') to hold
the bits onto the hub ?

Tim




On Thu, 7 Nov 2019 at 12:36, Chuck Harris <cfharris@...> wrote:

Because the plastic has shrunk, you need to increase
the space for the center hub. The easiest way I have
found is to assemble the parts as well as you can, and
then wrap some rubber bands around the knob to provide
tension.

Then take a soldering iron, and heat the center hub.

The instant the plastic relaxes, remove the heat, and
cool the hub by blowing on it.

After all is done, a drop of acrylic solvent glue will,
seal the deal, so to speak.

-Chuck Harris


Re: Knob repair tips

Tim Phillips
 

from Tim P (UK)
................ or use an adjustable hose-clamp ('Jubilee clip') to hold
the bits onto the hub ?

Tim

On Thu, 7 Nov 2019 at 12:36, Chuck Harris <cfharris@...> wrote:

Because the plastic has shrunk, you need to increase
the space for the center hub. The easiest way I have
found is to assemble the parts as well as you can, and
then wrap some rubber bands around the knob to provide
tension.

Then take a soldering iron, and heat the center hub.

The instant the plastic relaxes, remove the heat, and
cool the hub by blowing on it.

After all is done, a drop of acrylic solvent glue will,
seal the deal, so to speak.

-Chuck Harris

Dave Voorhis wrote:
I just acquired a Telequipment (British subsidiary of Tek in the
60’s/70’s) CT71 curve tracer in excellent working condition and good
cosmetic shape, but for a cracked knob. Like the usual Tek knobs, it’s a
plastic shell around a linear-knurled metal core. The plastic appears to
have shrunk slightly, causing it to crack and no longer grip the core.

If I recall correctly, someone posted tips on this forum on how to
permanently repair such shrink-cracked knobs, but my search-fu must be
broken today because I can’t find the relevant posts.

Can anyone can give me a quick recap and/or point me to the posts on
groups.io <http://groups.io/>?






Re: Knob repair tips

Chuck Harris
 

Because the plastic has shrunk, you need to increase
the space for the center hub. The easiest way I have
found is to assemble the parts as well as you can, and
then wrap some rubber bands around the knob to provide
tension.

Then take a soldering iron, and heat the center hub.

The instant the plastic relaxes, remove the heat, and
cool the hub by blowing on it.

After all is done, a drop of acrylic solvent glue will,
seal the deal, so to speak.

-Chuck Harris

Dave Voorhis wrote:

I just acquired a Telequipment (British subsidiary of Tek in the 60’s/70’s) CT71 curve tracer in excellent working condition and good cosmetic shape, but for a cracked knob. Like the usual Tek knobs, it’s a plastic shell around a linear-knurled metal core. The plastic appears to have shrunk slightly, causing it to crack and no longer grip the core.

If I recall correctly, someone posted tips on this forum on how to permanently repair such shrink-cracked knobs, but my search-fu must be broken today because I can’t find the relevant posts.

Can anyone can give me a quick recap and/or point me to the posts on groups.io <http://groups.io/>?




Re: Knob repair tips

 

I don't know any posts references but these two seem most appropriate and have worked for me:

1. If the parts still (almost) close around the knurled Al hub, fit the plastic parts and apply very little very-low viscosity superglue. Use epoxy in case of gaps between plastic pieces.

2. Chuck Harris came up with this brilliant suggestion a while ago: Pre-fit the plastic pieces around the Al core. Carefully heat the core to just soften the plastic and press plastic parts further in (use either fingers or an elastic band or such thing). If deemed necessary, apply a small amount of very-low viscosity superglue afterward, between core and plastic.

Raymond


Knob repair tips

Dave Voorhis
 

I just acquired a Telequipment (British subsidiary of Tek in the 60’s/70’s) CT71 curve tracer in excellent working condition and good cosmetic shape, but for a cracked knob. Like the usual Tek knobs, it’s a plastic shell around a linear-knurled metal core. The plastic appears to have shrunk slightly, causing it to crack and no longer grip the core.

If I recall correctly, someone posted tips on this forum on how to permanently repair such shrink-cracked knobs, but my search-fu must be broken today because I can’t find the relevant posts.

Can anyone can give me a quick recap and/or point me to the posts on groups.io <http://groups.io/>?


Re: TDS3044B repair

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.











Re: OT: A Spring trip!

Richard R. Pope
 

Hello all,
BTW: Reedsburg area includes Chicago, Milwaukee, Madison, Minneapolis, Dubuque, or any other towns or cities within 300 miles.
GOD Bless and Thanks,
rich!

On 11/6/2019 9:22 PM, Richard R. Pope wrote:
Hello all,
I am looking for someone in the Reedsburg, WI area that would like to take a road trip out West come this spring. Say sometime in late May or early June. If you are interested please let me know. Non-smoker only.
GOD Bless and Thanks,

Richard R. Pope
1230 19th Street #5
Reedsburg, WI 53959, USA
1-608-768-7448
mechanic_2@...




OT: A Spring trip!

Richard R. Pope
 

Hello all,
I am looking for someone in the Reedsburg, WI area that would like to take a road trip out West come this spring. Say sometime in late May or early June. If you are interested please let me know. Non-smoker only.
GOD Bless and Thanks,

Richard R. Pope
1230 19th Street #5
Reedsburg, WI 53959, USA
1-608-768-7448
mechanic_2@...


Re: TDS3044B repair

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.