Could someone please help me and give some hints ?
After years of unuse I am now restoring an old APPLE ][ plus, RFI Revision "D". When I put in the DISK ][ Interface (650-X104-) it works, but I see some vertical lines on the screen. Have a look at the foto please. These lines become darker if the drive motor spins and are colmpletely gone if I pull out the interface.
I had to replace a few RAM chips (4116) and one ROM was gone but now, ROM, RAM and PROMS on the DISK interface all test good.
Where should I start with ? Probably there is a component which is more suspect than the others.
Thanks in advance