Grey screen on a 7400

Buffett

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Donor 2012-2013
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did some searching and could not find an answer to this issue.

i have a 7400 that has been capped and the B+ and Video B+ are correct.
it has the old flyback.

but the problem is that the screen is grey:confused:

i have some contrast control and some brightness control on the remote board. the flyback brightness control is fine.
and the tube has ben checked and is fine.

i have turned up the guns on the tube individually so you can see that they are fine. but the whole image is still grey.

ignore the convergence i know it is off and will adjust it after i get all the image back properly.

i have swapped neck boards and the problem persists.

my suspicion is that it is one of the IC's on the chassis is bad, but don't want to assume to much.

The screen as it is grey.

scaled.php


Red pot turned up on the neck you can see the game still there but is grey.

scaled.php


Green pot turned up on the neck you can see the game still there but is grey.

scaled.php


Blue pot turned up on the neck you can see the game still there but is grey.

scaled.php



Any idea's on this issue.

i am fixing it for a customer so any help would be great.

Peace
Buffett
 
isn't that an R811 issue?

fairly certain some resistor causes that. going to guesstimate it's somewhere over by the signal header, since the CRT itself is working fine.

I tried looking in one of the troubleshooting guides at WG, but it wasn't listed.
 
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