This is my first post on Applefritter. I've used many enjoyable hours reviewing all the excellent posts on Applefritter, as well as the extremely helpful trouble shoot guide at http://www.appleii-box.de.
My rev 4 apple ii that came from the UK has display problems! Everything seems fine for the most part--system beeps, boots, keyboard is responsive, etc--EXCEPT the video is scrambled with vertical lines. See attached photos.
Things I have done:
1) Replaced the crystal/oscillator to be 14.31818 MHZ. I've tried both a new crystal and a working crystal from an Apple ii+
2) Completed the X and O soldering to convert from PAL to NTSC
It's worth noting it had video problems before the above changes when using a PAL to NTSC converter box, so I believe the problem lies elsewhere. I believe the PAL to NTSC is successful
Things I have tried to fix the problem
3) Removed all cards and RAM, except RAM row 1
4) Swap many (if not all) IC from a working Apple ii+ including RAM, dataline chips, ROM chips, databus chips, etc outlined in the troubleshoot guide
No matter what I change in steps 3 and 4 I get the same video problem.
Thanks in advance for any help