Topics

2445 LVPS Issues


n4buq
 

I was using my 2445 today when I heard a strange sort of thump noise coming from inside the scope after which I started smelling a burning odor. I had a few pieces of gear powered up at the time but quickly could tell the smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is coming from the LVPS board(s) but am a bit stumped at how to get those two boards out. I'm pretty sure the top ribbon cable needs to come off but don't quite see how to get the large plastic cover off of the area where the main filter caps are.

Looking at some of the smaller caps, they appear to be leaning due to (I'm guessing) bulging at the circuit board end but not sure exactly what overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove those boards? If not, could someone provide a couple of hints to get me started?

Thanks,
Barry - N4BUQ


Tom Gardner
 

The service manual is quite specific on how to remove the various boards. It isn't difficult, if follow instructions.

The manual is available at the usual places, e.g. tekwiki.

Be aware that on some of the 24x5* series the manual and silk screen show two caps swapped. So when recapping, remove and replace a single capacitor before moving on to the next; don't remove them all and then start replacing them.

On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump noise coming from inside the scope after which I started smelling a burning odor. I had a few pieces of gear powered up at the time but quickly could tell the smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is coming from the LVPS board(s) but am a bit stumped at how to get those two boards out. I'm pretty sure the top ribbon cable needs to come off but don't quite see how to get the large plastic cover off of the area where the main filter caps are.

Looking at some of the smaller caps, they appear to be leaning due to (I'm guessing) bulging at the circuit board end but not sure exactly what overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove those boards? If not, could someone provide a couple of hints to get me started?

Thanks,
Barry - N4BUQ


tom jobe <tomjobe@...>
 

If you are talking about the black cover over the two largest capacitors, there is a prong that goes down in the middle between the two bumps, the prong has a hook on one side of it that latches the cover in place. You deflect the prong to the side a little bit and the cover comes off in your hand. Maybe wait until you have the power supply out on the bench before trying to remove the black cover?
Those two large capacitors never seem to give any trouble in a 24x5 but have a look anyway and check the ESR if it is easy for you to do. Replace all of the smaller caps regardless of how they look or the ESR checks out. I see you have been warned about the schematic errors on two of the capacitors, don't miss this problem.
There is excellent help available here on Tekscopes for the 24x5 scope family.

On 8/3/2019 4:13 PM, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump noise coming from inside the scope after which I startettd smelling a burning odor. I had a few pieces of gear powered up at the time but quickly could tell the smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is coming from the LVPS board(s) but am a bit stumped at how to get those two boards out. I'm pretty sure the top ribbon cable needs to come off but don't quite see how to get the large plastic cover off of the area where the main filter caps are.

Looking at some of the smaller caps, they appear to be leaning due to (I'm guessing) bulging at the circuit board end but not sure exactly what overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove those boards? If not, could someone provide a couple of hints to get me started?

Thanks,
Barry - N4BUQ



n4buq
 

I didn't realize the SM would go into detail on board removal. I will read up on it there.

Thanks for the tip on the incorrect silkscreen too.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Gardner" <tggzzz@gmail.com>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

The service manual is quite specific on how to remove the various boards. It
isn't difficult, if follow instructions.

The manual is available at the usual places, e.g. tekwiki.

Be aware that on some of the 24x5* series the manual and silk screen show two
caps swapped. So when recapping, remove and replace a single capacitor before
moving on to the next; don't remove them all and then start replacing them.


On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump noise coming
from inside the scope after which I started smelling a burning odor. I
had a few pieces of gear powered up at the time but quickly could tell the
smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is coming from
the LVPS board(s) but am a bit stumped at how to get those two boards out.
I'm pretty sure the top ribbon cable needs to come off but don't quite
see how to get the large plastic cover off of the area where the main
filter caps are.

Looking at some of the smaller caps, they appear to be leaning due to (I'm
guessing) bulging at the circuit board end but not sure exactly what
overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove those boards?
If not, could someone provide a couple of hints to get me started?

Thanks,
Barry - N4BUQ




n4buq
 

I was under the impression that the black cover would not allow the boards to be removed beforehand but if that's the case, then okay. I see to recall removing that before on perhaps a different scope but just didn't see how to get it out this time.

I'll check the ESR on the big caps as well. Good to know that those may not need replacing. As I said, I'm pretty sure I see bulging on several of the smaller caps on the regulator(?) board so will plan to replace all of them.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "tom jobe" <tomjobe@gmail.com>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 7:29:21 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

If you are talking about the black cover over the two largest
capacitors, there is a prong that goes down in the middle between the
two bumps, the prong has a hook on one side of it that latches the cover
in place. You deflect the prong to the side a little bit and the cover
comes off in your hand. Maybe wait until you have the power supply out
on the bench before trying to remove the black cover?
Those two large capacitors never seem to give any trouble in a 24x5 but
have a look anyway and check the ESR if it is easy for you to do.
Replace all of the smaller caps regardless of how they look or the ESR
checks out. I see you have been warned about the schematic errors on two
of the capacitors, don't miss this problem.
There is excellent help available here on Tekscopes for the 24x5 scope
family.


On 8/3/2019 4:13 PM, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump noise coming
from inside the scope after which I startettd smelling a burning odor. I
had a few pieces of gear powered up at the time but quickly could tell the
smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is coming from
the LVPS board(s) but am a bit stumped at how to get those two boards out.
I'm pretty sure the top ribbon cable needs to come off but don't quite
see how to get the large plastic cover off of the area where the main
filter caps are.

Looking at some of the smaller caps, they appear to be leaning due to (I'm
guessing) bulging at the circuit board end but not sure exactly what
overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove those boards?
If not, could someone provide a couple of hints to get me started?

Thanks,
Barry - N4BUQ







n4buq
 

And there, on page 6-25, is the complete process spelled out very neatly. Just didn't expect that.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "n4buq" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

I didn't realize the SM would go into detail on board removal. I will read
up on it there.

Thanks for the tip on the incorrect silkscreen too.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Gardner" <tggzzz@gmail.com>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

The service manual is quite specific on how to remove the various boards.
It
isn't difficult, if follow instructions.

The manual is available at the usual places, e.g. tekwiki.

Be aware that on some of the 24x5* series the manual and silk screen show
two
caps swapped. So when recapping, remove and replace a single capacitor
before
moving on to the next; don't remove them all and then start replacing them.


On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump noise
coming
from inside the scope after which I started smelling a burning odor. I
had a few pieces of gear powered up at the time but quickly could tell
the
smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is coming
from
the LVPS board(s) but am a bit stumped at how to get those two boards
out.
I'm pretty sure the top ribbon cable needs to come off but don't quite
see how to get the large plastic cover off of the area where the main
filter caps are.

Looking at some of the smaller caps, they appear to be leaning due to
(I'm
guessing) bulging at the circuit board end but not sure exactly what
overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove those boards?
If not, could someone provide a couple of hints to get me started?

Thanks,
Barry - N4BUQ






Chuck Harris <cfharris@...>
 

Two different black covers. The one over the mains input
has a couple of screws through the back panel, and then it
lifts off and out.

-Chuck Harris


n4buq wrote:

I was under the impression that the black cover would not allow the boards to be removed beforehand but if that's the case, then okay. I see to recall removing that before on perhaps a different scope but just didn't see how to get it out this time.

I'll check the ESR on the big caps as well. Good to know that those may not need replacing. As I said, I'm pretty sure I see bulging on several of the smaller caps on the regulator(?) board so will plan to replace all of them.

Thanks,
Barry - N4BUQ


 

This project of mine might provide some useful info.
https://hackaday.io/project/163890-tektronix-2465-series-servicing
AB


Tony Fleming
 

Thank you very much! Tony

On Sun, Aug 4, 2019 at 5:47 PM Ancel <protofabtt@gmail.com> wrote:

This project of mine might provide some useful info.
https://hackaday.io/project/163890-tektronix-2465-series-servicing
AB




n4buq
 

Got everything removed except the fan. Any hints/tricks to getting that off? Loosened the nut but the fan blade won't budge and I don't want to pull any harder unless it is recommended. I have a feeling that's some kind of collet and perhaps pressure on the slotted screw would release it but just don't know.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Barry" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

And there, on page 6-25, is the complete process spelled out very neatly.
Just didn't expect that.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "n4buq" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

I didn't realize the SM would go into detail on board removal. I will read
up on it there.

Thanks for the tip on the incorrect silkscreen too.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Gardner" <tggzzz@gmail.com>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

The service manual is quite specific on how to remove the various boards.
It
isn't difficult, if follow instructions.

The manual is available at the usual places, e.g. tekwiki.

Be aware that on some of the 24x5* series the manual and silk screen show
two
caps swapped. So when recapping, remove and replace a single capacitor
before
moving on to the next; don't remove them all and then start replacing
them.


On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump noise
coming
from inside the scope after which I started smelling a burning odor. I
had a few pieces of gear powered up at the time but quickly could tell
the
smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is coming
from
the LVPS board(s) but am a bit stumped at how to get those two boards
out.
I'm pretty sure the top ribbon cable needs to come off but don't quite
see how to get the large plastic cover off of the area where the main
filter caps are.

Looking at some of the smaller caps, they appear to be leaning due to
(I'm
guessing) bulging at the circuit board end but not sure exactly what
overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove those
boards?
If not, could someone provide a couple of hints to get me started?

Thanks,
Barry - N4BUQ






Tony Fleming
 

They are VERY FRAGILE! Do not apply much pressure or it just brakes.
I don't know how to remove it without braking it, sorry!

On Sun, Aug 4, 2019 at 7:13 PM n4buq <n4buq@knology.net> wrote:

Got everything removed except the fan. Any hints/tricks to getting that
off? Loosened the nut but the fan blade won't budge and I don't want to
pull any harder unless it is recommended. I have a feeling that's some
kind of collet and perhaps pressure on the slotted screw would release it
but just don't know.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Barry" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

And there, on page 6-25, is the complete process spelled out very neatly.
Just didn't expect that.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "n4buq" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

I didn't realize the SM would go into detail on board removal. I will
read
up on it there.

Thanks for the tip on the incorrect silkscreen too.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Gardner" <tggzzz@gmail.com>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

The service manual is quite specific on how to remove the various
boards.
It
isn't difficult, if follow instructions.

The manual is available at the usual places, e.g. tekwiki.

Be aware that on some of the 24x5* series the manual and silk screen
show
two
caps swapped. So when recapping, remove and replace a single
capacitor
before
moving on to the next; don't remove them all and then start replacing
them.


On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump
noise
coming
from inside the scope after which I started smelling a burning
odor. I
had a few pieces of gear powered up at the time but quickly could
tell
the
smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is
coming
from
the LVPS board(s) but am a bit stumped at how to get those two
boards
out.
I'm pretty sure the top ribbon cable needs to come off but don't
quite
see how to get the large plastic cover off of the area where the
main
filter caps are.

Looking at some of the smaller caps, they appear to be leaning due
to
(I'm
guessing) bulging at the circuit board end but not sure exactly
what
overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove those
boards?
If not, could someone provide a couple of hints to get me started?

Thanks,
Barry - N4BUQ








n4buq
 

I've already pulled on it harder than I was really comfortable doing; however, the instructions state to use "firm pressure" to pull the fan blade off.

I'm wondering if the slotted screw is intended to be used to push against the motor shaft and push the fan blade off. If that were the case, though, I'd think that would be in the instructions so I'm thinking that's not a proper approach.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tony Fleming" <czecht@gmail.com>
To: TekScopes@groups.io
Sent: Sunday, August 4, 2019 7:44:33 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

They are VERY FRAGILE! Do not apply much pressure or it just brakes.
I don't know how to remove it without braking it, sorry!

On Sun, Aug 4, 2019 at 7:13 PM n4buq <n4buq@knology.net> wrote:

Got everything removed except the fan. Any hints/tricks to getting that
off? Loosened the nut but the fan blade won't budge and I don't want to
pull any harder unless it is recommended. I have a feeling that's some
kind of collet and perhaps pressure on the slotted screw would release it
but just don't know.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Barry" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

And there, on page 6-25, is the complete process spelled out very neatly.
Just didn't expect that.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "n4buq" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

I didn't realize the SM would go into detail on board removal. I will
read
up on it there.

Thanks for the tip on the incorrect silkscreen too.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Gardner" <tggzzz@gmail.com>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

The service manual is quite specific on how to remove the various
boards.
It
isn't difficult, if follow instructions.

The manual is available at the usual places, e.g. tekwiki.

Be aware that on some of the 24x5* series the manual and silk screen
show
two
caps swapped. So when recapping, remove and replace a single
capacitor
before
moving on to the next; don't remove them all and then start replacing
them.


On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump
noise
coming
from inside the scope after which I started smelling a burning
odor. I
had a few pieces of gear powered up at the time but quickly could
tell
the
smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is
coming
from
the LVPS board(s) but am a bit stumped at how to get those two
boards
out.
I'm pretty sure the top ribbon cable needs to come off but don't
quite
see how to get the large plastic cover off of the area where the
main
filter caps are.

Looking at some of the smaller caps, they appear to be leaning due
to
(I'm
guessing) bulging at the circuit board end but not sure exactly
what
overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove those
boards?
If not, could someone provide a couple of hints to get me started?

Thanks,
Barry - N4BUQ










Tony Fleming
 

I did not remove mine, when fixing mine. It was little dusty so I used a
brush. It works, so I don't fix what isn't broken.... ha ha ha
BUT my memory isn't that good to remember if it is glued or some set-screw
- sorry.
Is your fan working?

On Sun, Aug 4, 2019 at 9:32 PM n4buq <n4buq@knology.net> wrote:

I've already pulled on it harder than I was really comfortable doing;
however, the instructions state to use "firm pressure" to pull the fan
blade off.

I'm wondering if the slotted screw is intended to be used to push against
the motor shaft and push the fan blade off. If that were the case, though,
I'd think that would be in the instructions so I'm thinking that's not a
proper approach.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tony Fleming" <czecht@gmail.com>
To: TekScopes@groups.io
Sent: Sunday, August 4, 2019 7:44:33 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

They are VERY FRAGILE! Do not apply much pressure or it just brakes.
I don't know how to remove it without braking it, sorry!

On Sun, Aug 4, 2019 at 7:13 PM n4buq <n4buq@knology.net> wrote:

Got everything removed except the fan. Any hints/tricks to getting
that
off? Loosened the nut but the fan blade won't budge and I don't want
to
pull any harder unless it is recommended. I have a feeling that's some
kind of collet and perhaps pressure on the slotted screw would release
it
but just don't know.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Barry" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

And there, on page 6-25, is the complete process spelled out very
neatly.
Just didn't expect that.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "n4buq" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

I didn't realize the SM would go into detail on board removal. I
will
read
up on it there.

Thanks for the tip on the incorrect silkscreen too.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Gardner" <tggzzz@gmail.com>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

The service manual is quite specific on how to remove the various
boards.
It
isn't difficult, if follow instructions.

The manual is available at the usual places, e.g. tekwiki.

Be aware that on some of the 24x5* series the manual and silk
screen
show
two
caps swapped. So when recapping, remove and replace a single
capacitor
before
moving on to the next; don't remove them all and then start
replacing
them.


On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump
noise
coming
from inside the scope after which I started smelling a burning
odor. I
had a few pieces of gear powered up at the time but quickly
could
tell
the
smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is
coming
from
the LVPS board(s) but am a bit stumped at how to get those two
boards
out.
I'm pretty sure the top ribbon cable needs to come off but
don't
quite
see how to get the large plastic cover off of the area where
the
main
filter caps are.

Looking at some of the smaller caps, they appear to be leaning
due
to
(I'm
guessing) bulging at the circuit board end but not sure exactly
what
overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove
those
boards?
If not, could someone provide a couple of hints to get me
started?

Thanks,
Barry - N4BUQ












n4buq
 

The fan was working - at least I'm pretty sure it was. Something in the PS began to smell of smoke so I'm pulling it to perform needed repair and maintenance work (mostly capacitor replacements).

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tony Fleming" <czecht@gmail.com>
To: TekScopes@groups.io
Sent: Sunday, August 4, 2019 10:17:23 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

I did not remove mine, when fixing mine. It was little dusty so I used a
brush. It works, so I don't fix what isn't broken.... ha ha ha
BUT my memory isn't that good to remember if it is glued or some set-screw
- sorry.
Is your fan working?

On Sun, Aug 4, 2019 at 9:32 PM n4buq <n4buq@knology.net> wrote:

I've already pulled on it harder than I was really comfortable doing;
however, the instructions state to use "firm pressure" to pull the fan
blade off.

I'm wondering if the slotted screw is intended to be used to push against
the motor shaft and push the fan blade off. If that were the case, though,
I'd think that would be in the instructions so I'm thinking that's not a
proper approach.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tony Fleming" <czecht@gmail.com>
To: TekScopes@groups.io
Sent: Sunday, August 4, 2019 7:44:33 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

They are VERY FRAGILE! Do not apply much pressure or it just brakes.
I don't know how to remove it without braking it, sorry!

On Sun, Aug 4, 2019 at 7:13 PM n4buq <n4buq@knology.net> wrote:

Got everything removed except the fan. Any hints/tricks to getting
that
off? Loosened the nut but the fan blade won't budge and I don't want
to
pull any harder unless it is recommended. I have a feeling that's some
kind of collet and perhaps pressure on the slotted screw would release
it
but just don't know.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Barry" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

And there, on page 6-25, is the complete process spelled out very
neatly.
Just didn't expect that.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "n4buq" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

I didn't realize the SM would go into detail on board removal. I
will
read
up on it there.

Thanks for the tip on the incorrect silkscreen too.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Gardner" <tggzzz@gmail.com>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

The service manual is quite specific on how to remove the various
boards.
It
isn't difficult, if follow instructions.

The manual is available at the usual places, e.g. tekwiki.

Be aware that on some of the 24x5* series the manual and silk
screen
show
two
caps swapped. So when recapping, remove and replace a single
capacitor
before
moving on to the next; don't remove them all and then start
replacing
them.


On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump
noise
coming
from inside the scope after which I started smelling a burning
odor. I
had a few pieces of gear powered up at the time but quickly
could
tell
the
smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is
coming
from
the LVPS board(s) but am a bit stumped at how to get those two
boards
out.
I'm pretty sure the top ribbon cable needs to come off but
don't
quite
see how to get the large plastic cover off of the area where
the
main
filter caps are.

Looking at some of the smaller caps, they appear to be leaning
due
to
(I'm
guessing) bulging at the circuit board end but not sure exactly
what
overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove
those
boards?
If not, could someone provide a couple of hints to get me
started?

Thanks,
Barry - N4BUQ














Bob Albert
 

If you can do it, perhaps gripping the fan motor shaft with a big pliers and wobbling the blade may help.  Wobble it back and forth numerous times but never with much force.
I have a problem with the main tuning knob on my TS-940S.  I can't undo the set screw.  It seems to be bunged up and so far nothing has budged it.  Luckily I have no need to remove it but still...
Bob

On Sunday, August 4, 2019, 09:14:38 PM PDT, n4buq <n4buq@knology.net> wrote:

The fan was working - at least I'm pretty sure it was.  Something in the PS began to smell of smoke so I'm pulling it to perform needed repair and maintenance work (mostly capacitor replacements).

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tony Fleming" <czecht@gmail.com>
To: TekScopes@groups.io
Sent: Sunday, August 4, 2019 10:17:23 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

I did not remove mine, when fixing mine. It was little dusty so I used a
brush. It works, so I don't fix what isn't broken.... ha ha ha
BUT my memory isn't that good to remember if it is glued or some set-screw
- sorry.
Is your fan working?

On Sun, Aug 4, 2019 at 9:32 PM n4buq <n4buq@knology.net> wrote:

I've already pulled on it harder than I was really comfortable doing;
however, the instructions state to use "firm pressure" to pull the fan
blade off.

I'm wondering if the slotted screw is intended to be used to push against
the motor shaft and push the fan blade off.  If that were the case, though,
I'd think that would be in the instructions so I'm thinking that's not a
proper approach.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tony Fleming" <czecht@gmail.com>
To: TekScopes@groups.io
Sent: Sunday, August 4, 2019 7:44:33 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

They are VERY FRAGILE! Do not apply much pressure or it just brakes.
I don't know how to remove it without braking it, sorry!

On Sun, Aug 4, 2019 at 7:13 PM n4buq <n4buq@knology.net> wrote:

Got everything removed except the fan.  Any hints/tricks to getting
that
off?  Loosened the nut but the fan blade won't budge and I don't want
to
pull any harder unless it is recommended.  I have a feeling that's some
kind of collet and perhaps pressure on the slotted screw would release
it
but just don't know.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Barry" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

And there, on page 6-25, is the complete process spelled out very
neatly.
Just didn't expect that.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "n4buq" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

I didn't realize the SM would go into detail on board removal.  I
will
read
up on it there.

Thanks for the tip on the incorrect silkscreen too.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Gardner" <tggzzz@gmail.com>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

The service manual is quite specific on how to remove the various
boards.
It
isn't difficult, if follow instructions.

The manual is available at the usual places, e.g. tekwiki.

Be aware that on some of the 24x5* series the manual and silk
screen
show
two
caps swapped. So when recapping, remove and replace a single
capacitor
before
moving on to the next; don't remove them all and then start
replacing
them.


On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump
noise
coming
from inside the scope after which I started smelling a burning
odor.  I
had a few pieces of gear powered up at the time but quickly
could
tell
the
smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is
coming
from
the LVPS board(s) but am a bit stumped at how to get those two
boards
out.
I'm pretty sure the top ribbon cable needs to come off but
don't
quite
see how to get the large plastic cover off of the area where
the
main
filter caps are.

Looking at some of the smaller caps, they appear to be leaning
due
to
(I'm
guessing) bulging at the circuit board end but not sure exactly
what
overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove
those
boards?
If not, could someone provide a couple of hints to get me
started?

Thanks,
Barry - N4BUQ














Chuck Harris <cfharris@...>
 

It is easy:

Put a screwdriver in the slot of the screw, and use a wrench to
turn the nut against the screw (DON't LET THE SCREW TURN!!!)

Back off the nut until it is flush with the slot, and give the
nut a light tap with a hammer. It will move into the squirrel
cage a little bit, and then the squirrel cage can be pulled off.

If you let the screw turn relative to the squirrel cage, it will
destroy the delicate plastic collet... you don't want to do that!

-Chuck Harris

n4buq wrote:

Got everything removed except the fan. Any hints/tricks to getting that off? Loosened the nut but the fan blade won't budge and I don't want to pull any harder unless it is recommended. I have a feeling that's some kind of collet and perhaps pressure on the slotted screw would release it but just don't know.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Barry" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

And there, on page 6-25, is the complete process spelled out very neatly.
Just didn't expect that.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "n4buq" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

I didn't realize the SM would go into detail on board removal. I will read
up on it there.

Thanks for the tip on the incorrect silkscreen too.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Gardner" <tggzzz@gmail.com>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

The service manual is quite specific on how to remove the various boards.
It
isn't difficult, if follow instructions.

The manual is available at the usual places, e.g. tekwiki.

Be aware that on some of the 24x5* series the manual and silk screen show
two
caps swapped. So when recapping, remove and replace a single capacitor
before
moving on to the next; don't remove them all and then start replacing
them.


On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump noise
coming
from inside the scope after which I started smelling a burning odor. I
had a few pieces of gear powered up at the time but quickly could tell
the
smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is coming
from
the LVPS board(s) but am a bit stumped at how to get those two boards
out.
I'm pretty sure the top ribbon cable needs to come off but don't quite
see how to get the large plastic cover off of the area where the main
filter caps are.

Looking at some of the smaller caps, they appear to be leaning due to
(I'm
guessing) bulging at the circuit board end but not sure exactly what
overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove those
boards?
If not, could someone provide a couple of hints to get me started?

Thanks,
Barry - N4BUQ








Chuck Harris <cfharris@...>
 

OMG!!!

I surely hope you haven't followed any of these suggestions!

It is easy, loosen the nut, do not let the screw turn,
level the nut with the screw slot, tap it with a tiny
hammer, and it will fall off.

The screw is not threaded into the impeller. It is purely
there to pull the collet into a taper that is inside of the
impeller. The nut does the pulling.

DO NOT ALLOW THE SCREW TO TURN!!!
DO NOT yank, pull, or pry on the impeller.

-Chuck Harris

Bob Albert via Groups.Io wrote:

If you can do it, perhaps gripping the fan motor shaft with a big pliers and wobbling the blade may help. Wobble it back and forth numerous times but never with much force.
I have a problem with the main tuning knob on my TS-940S. I can't undo the set screw. It seems to be bunged up and so far nothing has budged it. Luckily I have no need to remove it but still...
Bob
On Sunday, August 4, 2019, 09:14:38 PM PDT, n4buq <n4buq@knology.net> wrote:

The fan was working - at least I'm pretty sure it was. Something in the PS began to smell of smoke so I'm pulling it to perform needed repair and maintenance work (mostly capacitor replacements).

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tony Fleming" <czecht@gmail.com>
To: TekScopes@groups.io
Sent: Sunday, August 4, 2019 10:17:23 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

I did not remove mine, when fixing mine. It was little dusty so I used a
brush. It works, so I don't fix what isn't broken.... ha ha ha
BUT my memory isn't that good to remember if it is glued or some set-screw
- sorry.
Is your fan working?

On Sun, Aug 4, 2019 at 9:32 PM n4buq <n4buq@knology.net> wrote:

I've already pulled on it harder than I was really comfortable doing;
however, the instructions state to use "firm pressure" to pull the fan
blade off.

I'm wondering if the slotted screw is intended to be used to push against
the motor shaft and push the fan blade off. If that were the case, though,
I'd think that would be in the instructions so I'm thinking that's not a
proper approach.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tony Fleming" <czecht@gmail.com>
To: TekScopes@groups.io
Sent: Sunday, August 4, 2019 7:44:33 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

They are VERY FRAGILE! Do not apply much pressure or it just brakes.
I don't know how to remove it without braking it, sorry!

On Sun, Aug 4, 2019 at 7:13 PM n4buq <n4buq@knology.net> wrote:

Got everything removed except the fan. Any hints/tricks to getting
that
off? Loosened the nut but the fan blade won't budge and I don't want
to
pull any harder unless it is recommended. I have a feeling that's some
kind of collet and perhaps pressure on the slotted screw would release
it
but just don't know.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Barry" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

And there, on page 6-25, is the complete process spelled out very
neatly.
Just didn't expect that.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "n4buq" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

I didn't realize the SM would go into detail on board removal. I
will
read
up on it there.

Thanks for the tip on the incorrect silkscreen too.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Gardner" <tggzzz@gmail.com>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

The service manual is quite specific on how to remove the various
boards.
It
isn't difficult, if follow instructions.

The manual is available at the usual places, e.g. tekwiki.

Be aware that on some of the 24x5* series the manual and silk
screen
show
two
caps swapped. So when recapping, remove and replace a single
capacitor
before
moving on to the next; don't remove them all and then start
replacing
them.


On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump
noise
coming
from inside the scope after which I started smelling a burning
odor. I
had a few pieces of gear powered up at the time but quickly
could
tell
the
smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is
coming
from
the LVPS board(s) but am a bit stumped at how to get those two
boards
out.
I'm pretty sure the top ribbon cable needs to come off but
don't
quite
see how to get the large plastic cover off of the area where
the
main
filter caps are.

Looking at some of the smaller caps, they appear to be leaning
due
to
(I'm
guessing) bulging at the circuit board end but not sure exactly
what
overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove
those
boards?
If not, could someone provide a couple of hints to get me
started?

Thanks,
Barry - N4BUQ



















n4buq
 

Okay, Chuck. I presumed it was a collet but wasn't sure how to release it. Unfortunately, I did turn the screw some in a CCW direction and then back again so it sounds like I may have damaged the collet. Ugh! Too tempting and the manual doesn't give any caveats regarding that (only states not to remove the nut which I can't really see what that would hurt either but, perhaps, because it might bind on the slotted burrs and cause the screw to turn). If I can get the impeller off, I'll see what kind of damage I may have caused. The impellers are still available but I'm guessing the collet isn't.

Thanks again,
Barry - N4BUQ

----- Original Message -----
From: "Chuck Harris" <cfharris@erols.com>
To: TekScopes@groups.io
Sent: Monday, August 5, 2019 8:25:19 AM
Subject: Re: [TekScopes] 2445 LVPS Issues

It is easy:

Put a screwdriver in the slot of the screw, and use a wrench to
turn the nut against the screw (DON't LET THE SCREW TURN!!!)

Back off the nut until it is flush with the slot, and give the
nut a light tap with a hammer. It will move into the squirrel
cage a little bit, and then the squirrel cage can be pulled off.

If you let the screw turn relative to the squirrel cage, it will
destroy the delicate plastic collet... you don't want to do that!

-Chuck Harris

n4buq wrote:
Got everything removed except the fan. Any hints/tricks to getting that
off? Loosened the nut but the fan blade won't budge and I don't want to
pull any harder unless it is recommended. I have a feeling that's some
kind of collet and perhaps pressure on the slotted screw would release it
but just don't know.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Barry" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

And there, on page 6-25, is the complete process spelled out very neatly.
Just didn't expect that.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "n4buq" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

I didn't realize the SM would go into detail on board removal. I will
read
up on it there.

Thanks for the tip on the incorrect silkscreen too.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Gardner" <tggzzz@gmail.com>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

The service manual is quite specific on how to remove the various
boards.
It
isn't difficult, if follow instructions.

The manual is available at the usual places, e.g. tekwiki.

Be aware that on some of the 24x5* series the manual and silk screen
show
two
caps swapped. So when recapping, remove and replace a single capacitor
before
moving on to the next; don't remove them all and then start replacing
them.


On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump noise
coming
from inside the scope after which I started smelling a burning odor. I
had a few pieces of gear powered up at the time but quickly could tell
the
smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is coming
from
the LVPS board(s) but am a bit stumped at how to get those two boards
out.
I'm pretty sure the top ribbon cable needs to come off but don't quite
see how to get the large plastic cover off of the area where the main
filter caps are.

Looking at some of the smaller caps, they appear to be leaning due to
(I'm
guessing) bulging at the circuit board end but not sure exactly what
overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove those
boards?
If not, could someone provide a couple of hints to get me started?

Thanks,
Barry - N4BUQ










Tony Fleming
 

Test the fan by itself and ru it for 30 minutes and see if it stays just
worm. If it gets hot, you will need to replace it. Also, how freely it
spins? Is it like new or slight resistance?
Gooooooood luck!
Tony

On Sun, Aug 4, 2019 at 11:14 PM n4buq <n4buq@knology.net> wrote:

The fan was working - at least I'm pretty sure it was. Something in the
PS began to smell of smoke so I'm pulling it to perform needed repair and
maintenance work (mostly capacitor replacements).

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tony Fleming" <czecht@gmail.com>
To: TekScopes@groups.io
Sent: Sunday, August 4, 2019 10:17:23 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

I did not remove mine, when fixing mine. It was little dusty so I used a
brush. It works, so I don't fix what isn't broken.... ha ha ha
BUT my memory isn't that good to remember if it is glued or some
set-screw
- sorry.
Is your fan working?

On Sun, Aug 4, 2019 at 9:32 PM n4buq <n4buq@knology.net> wrote:

I've already pulled on it harder than I was really comfortable doing;
however, the instructions state to use "firm pressure" to pull the fan
blade off.

I'm wondering if the slotted screw is intended to be used to push
against
the motor shaft and push the fan blade off. If that were the case,
though,
I'd think that would be in the instructions so I'm thinking that's not
a
proper approach.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tony Fleming" <czecht@gmail.com>
To: TekScopes@groups.io
Sent: Sunday, August 4, 2019 7:44:33 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

They are VERY FRAGILE! Do not apply much pressure or it just brakes.
I don't know how to remove it without braking it, sorry!

On Sun, Aug 4, 2019 at 7:13 PM n4buq <n4buq@knology.net> wrote:

Got everything removed except the fan. Any hints/tricks to getting
that
off? Loosened the nut but the fan blade won't budge and I don't
want
to
pull any harder unless it is recommended. I have a feeling that's
some
kind of collet and perhaps pressure on the slotted screw would
release
it
but just don't know.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Barry" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

And there, on page 6-25, is the complete process spelled out very
neatly.
Just didn't expect that.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "n4buq" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

I didn't realize the SM would go into detail on board
removal. I
will
read
up on it there.

Thanks for the tip on the incorrect silkscreen too.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Gardner" <tggzzz@gmail.com>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

The service manual is quite specific on how to remove the
various
boards.
It
isn't difficult, if follow instructions.

The manual is available at the usual places, e.g. tekwiki.

Be aware that on some of the 24x5* series the manual and silk
screen
show
two
caps swapped. So when recapping, remove and replace a single
capacitor
before
moving on to the next; don't remove them all and then start
replacing
them.


On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of
thump
noise
coming
from inside the scope after which I started smelling a
burning
odor. I
had a few pieces of gear powered up at the time but quickly
could
tell
the
smell was coming from the 2445.

I took off the case and top cover and pretty sure the
smell is
coming
from
the LVPS board(s) but am a bit stumped at how to get those
two
boards
out.
I'm pretty sure the top ribbon cable needs to come off but
don't
quite
see how to get the large plastic cover off of the area
where
the
main
filter caps are.

Looking at some of the smaller caps, they appear to be
leaning
due
to
(I'm
guessing) bulging at the circuit board end but not sure
exactly
what
overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove
those
boards?
If not, could someone provide a couple of hints to get me
started?

Thanks,
Barry - N4BUQ
















n4buq
 

Searching for Tektronix "impeller" vs. "fan", I finally found a picture of the collet:

https://qservice.tv/vpasp/shopexd.asp?id=4199

That makes sense to me now. Still unsure how turning the screw damages the collet (presuming the fingers stick to the tapered ID of the impeller and a twisting motion breaks them) but I'm guessing I'll find out soon enough.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Barry" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Monday, August 5, 2019 9:12:01 AM
Subject: Re: [TekScopes] 2445 LVPS Issues

Okay, Chuck. I presumed it was a collet but wasn't sure how to release it.
Unfortunately, I did turn the screw some in a CCW direction and then back
again so it sounds like I may have damaged the collet. Ugh! Too tempting
and the manual doesn't give any caveats regarding that (only states not to
remove the nut which I can't really see what that would hurt either but,
perhaps, because it might bind on the slotted burrs and cause the screw to
turn). If I can get the impeller off, I'll see what kind of damage I may
have caused. The impellers are still available but I'm guessing the collet
isn't.

Thanks again,
Barry - N4BUQ

----- Original Message -----
From: "Chuck Harris" <cfharris@erols.com>
To: TekScopes@groups.io
Sent: Monday, August 5, 2019 8:25:19 AM
Subject: Re: [TekScopes] 2445 LVPS Issues

It is easy:

Put a screwdriver in the slot of the screw, and use a wrench to
turn the nut against the screw (DON't LET THE SCREW TURN!!!)

Back off the nut until it is flush with the slot, and give the
nut a light tap with a hammer. It will move into the squirrel
cage a little bit, and then the squirrel cage can be pulled off.

If you let the screw turn relative to the squirrel cage, it will
destroy the delicate plastic collet... you don't want to do that!

-Chuck Harris

n4buq wrote:
Got everything removed except the fan. Any hints/tricks to getting that
off? Loosened the nut but the fan blade won't budge and I don't want to
pull any harder unless it is recommended. I have a feeling that's some
kind of collet and perhaps pressure on the slotted screw would release it
but just don't know.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Barry" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:30:54 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

And there, on page 6-25, is the complete process spelled out very
neatly.
Just didn't expect that.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "n4buq" <n4buq@knology.net>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 9:03:44 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

I didn't realize the SM would go into detail on board removal. I will
read
up on it there.

Thanks for the tip on the incorrect silkscreen too.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Tom Gardner" <tggzzz@gmail.com>
To: TekScopes@groups.io
Sent: Saturday, August 3, 2019 7:10:03 PM
Subject: Re: [TekScopes] 2445 LVPS Issues

The service manual is quite specific on how to remove the various
boards.
It
isn't difficult, if follow instructions.

The manual is available at the usual places, e.g. tekwiki.

Be aware that on some of the 24x5* series the manual and silk screen
show
two
caps swapped. So when recapping, remove and replace a single capacitor
before
moving on to the next; don't remove them all and then start replacing
them.


On 04/08/19 00:13, n4buq wrote:
I was using my 2445 today when I heard a strange sort of thump noise
coming
from inside the scope after which I started smelling a burning odor.
I
had a few pieces of gear powered up at the time but quickly could
tell
the
smell was coming from the 2445.

I took off the case and top cover and pretty sure the smell is coming
from
the LVPS board(s) but am a bit stumped at how to get those two boards
out.
I'm pretty sure the top ribbon cable needs to come off but don't
quite
see how to get the large plastic cover off of the area where the main
filter caps are.

Looking at some of the smaller caps, they appear to be leaning due to
(I'm
guessing) bulging at the circuit board end but not sure exactly what
overheated (or, possibly, made that thumping noise).

Are there instructions somewhere that outline how to remove those
boards?
If not, could someone provide a couple of hints to get me started?

Thanks,
Barry - N4BUQ