A1200 Board Dim Colours/Display

Pghulme

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Hello
i have an A1200 Rev 1A board that starts just fine but the display is really dim. Am just wondering if anyone has any obvious solutions to this. It's not been recapped and am sure a lot of people's answer would be to recap it. None of the caps "look" bad, if it were a bad cap, rather than recapping the whole board, is there a particular cap that would cause this. Output is similar on RF and RGB port.
 
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I would suspect one of the ceramic caps lowering the reference voltage .
 
Yea, another site (http://eab.abime.net/showthread.php?t=47774) suggested it could be either the DAC (ADV101KP30) or D215 or C12A. I've ordered a DAC from china.

image.jpgIMG_3133.JPGScreen Shot 2015-10-18 at 10.33.29.jpg

ONLY PROBLEM IS I CANT SEE C12A, AND D215 RELATES TO AN IC?

any suggestions on what should be replaced
 
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C12A is on +VID rail, if it fails (low resistance) it will drag it down and all video circuits will have lower supply voltage. Diode is supplying reference voltage which is directly connected to DAC :). Measure +VID voltage - should be close to 5V - if not then one of the caps is faulty on +VID rail. Voltage drop on diode should be 1.2V
 
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Ok I'll check that tomorrow
just out of interest why does the diode drop the voltage by 1.2v ?
 
Update to this thread, I sent my board to bebek and he did a great job at repairing it. Really great service, board recapped and a faulty IC repaired.
Thanks so much, awesome job :)
 
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