I could really use some help with this IIe Platinum that I received as a donation since it was displaying garbage on the screen. I swapped the 6502 chip with an older IIe (which I hope is okay for testing. I also noticed the existing chip just says 6502 making me wonder if this was a donor board). Anyways, it solved the problem of displaying garbage and boots fine and passes the self test, however when I try booting with a Disk ][ interface card, it starts exhibiting some odd symptoms including failing to engage the drive (the red light begins to turn on for a half a second before disappearing). Also the boot itself is very odd in that the "Apple ][" characters appear very slowly as if by one pixel at a time.
At this point the self test produces an error of "RAM 00100000" which obviously leads me to believe this is a RAM problem. Does that sound right to everyone else? If so, is there a way to isolate which chip it may be and where a good place to replace them would be? I'd really love to see this thing up and running and I don't mind some soldering but I can't seem to find anything about that error.
I appreciate it very much! Thanks!