need help repairing sony gdm-20d10

[Aaron Solochek]

This is the second one of these monitors which has developed this
ghosting image problem. Actually, I'm not sure ghosting is the correct
word for it -- it looks as though the image is being displayed at two
horizontal offsets, and moving unevenly between them. I can't seem to
affect the problem by hitting the set, and I've verified its not the
source by testing other monitors.

The problem is not constant, sometimes it works just fine, sometimes its
nearly impossible to read. It _seems_ to happen less when I'm operating
at 1280x1024 in xwindows, but it does sometimes happen at that
resolution, too.

So I've decided to not trash this monitor like I did the last one. I
have a degree in electrical engineering, but don't know squat about CRT
repair other than "be careful, they store a lot of charge." I read
everything I could find online about it, and I think I should try to
replace the caps on the A board.

I have the power supply board out, but I'm not sure how to remove the A
board and don't want to take any risks on this thing. I haven't yet
discharged the CRT, and I'm not quite sure how, or if its even necessary
for removing this board. If someone could give me a few instructions on
removing this thing, I'd really appreciate it.

Thanks.

-Aaron

 

[Aaron Solochek]

This is the second one of these monitors which has developed this
ghosting image problem. Actually, I'm not sure ghosting is the correct
word for it -- it looks as though the image is being displayed at two
horizontal offsets, and moving unevenly between them. I can't seem to
affect the problem by hitting the set, and I've verified its not the
source by testing other monitors.

The problem is not constant, sometimes it works just fine, sometimes its
nearly impossible to read. It _seems_ to happen less when I'm operating
at 1280x1024 in xwindows, but it does sometimes happen at that
resolution, too.

So I've decided to not trash this monitor like I did the last one. I
have a degree in electrical engineering, but don't know squat about CRT
repair other than "be careful, they store a lot of charge." I read
everything I could find online about it, and I think I should try to
replace the caps on the A board.

I have the power supply board out, but I'm not sure how to remove the A
board and don't want to take any risks on this thing. I haven't yet
discharged the CRT, and I'm not quite sure how, or if its even necessary
for removing this board. If someone could give me a few instructions on
removing this thing, I'd really appreciate it.

Thanks.

-Aaron

I forgot to mention the other problem I'm hoping to fix while I have this
apart: The image is too far to the left, and rotated a significant
amount. User adjustments don't correct this, so if someone could give me
the quick guide to fixing those problems, that would be nice.

Just for the record, I'm trying to do this all myself because 1) I want
to learn some of the internals of these, and 2) I just want to keep this
monitor because it matches the ultra1 its attached to. If I can't fix
it, its getting replaced with a nicer viewsonic that I already have.

-Aaron

 

[David]

90% of the problems in that monitor model can be repaired by finding the
high esr capacitors and replacing them.

David

 

[GPG]

I forgot to mention the other problem I'm hoping to fix while I have this
apart: The image is too far to the left, and rotated a significant
amount. User adjustments don't correct this, so if someone could give me
the quick guide to fixing those problems, that would be nice.

Just for the record, I'm trying to do this all myself because 1) I want
to learn some of the internals of these, and 2) I just want to keep this
monitor because it matches the ultra1 its attached to. If I can't fix
it, its getting replaced with a nicer viewsonic that I already have.

-Aaron

Loose yoke