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Dave, check the power supply caps for high ESR and also all of the decoupling electrolytics on all the other boards. I helped restore a VA48 for a friend a few years back. Sadly, he's now about blind with macular degeneration, so it sits. Bad caps cause high ripple that interferes with the counter circuits they use for division in the VA48 - that's how they get the lines for crosshatch, etc. I shotgunned the caps, but later checked a few and realized I was dead on in getting them out. Some values had to be subbed with slightly higher values of capacity and voltage, IIRC. Standard values in the 70's aren't standard now, so subs were the way to go (3000uf got a 3300, etc.)
Cheers,
__________________
Brian
USN RET 22YRS (Avionics/Cal)
CET-Consumer Repair and Avionics ('88)
"Capacitor Cosmetologist since '79"
When fuses go to work, they quit!
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