IIci no video sometimes?

[Fred1212]

Have a recapped IIci that will chime and startup with video if it has RAM only in bank A. BUT occasionally it will boot OK with RAM in bank B as well. Mostly it will not start with Bank B filled and if it doesn't start and the RAM is removed from B I have to remove the supply and let it sit for quite a while sometimes hours before it will boot from just RAM in Bank A again. I have never had video from the onboard socket and have a Nubus card for video. I have tried filling Bank B only and get good chime, no video problem. The RAM is all good and tested working in other computers and I have tried different good sets with same problem. I've tried using Rominator instead of onboard ROM same outcome. Any thoughts on what are the likely suspects is appreciated

 

[Fred1212]

Looking at the schematic probably need to lift clean replace the UJ's

 

[finkmac]

IIci uses bank A for video memory. if you don't have memory in Bank A it should work fine but won't display video (obviously)

 

[Fred1212]

Thanks tried Bank B only still no go. Can't get it to display video at all now so whatever is causing it has gone from unreliable to dead