Dear all, I'm cleaning up this IIc + flat display and upgrading its ROM, but while it seems to work fine using the original ROM FF, once I open/short the PCB bridges and use one of the newer ROM versions, the result is a checkered screen (solid squares). Pressing CTRL+Open+Closed+Reset, makes the IIc beep and fills the squares with characters (See attached photos).
At some point, after power cycling the IIc, I ended up with a "RAM GLU 000101" message. I've seen it only once.
Powering on with or without the keyboard installed, results in the same checkered screen. Tried w/ ROM 00, 04 and 4x.
If indeed there's a hardware problem, is it worth finding a diagnostics floppy to execute w/ ROM FF, or should I start replacing the memory chips?
TIA
At some point, after power cycling the IIc, I ended up with a "RAM GLU 000101" message. I've seen it only once.
Powering on with or without the keyboard installed, results in the same checkered screen. Tried w/ ROM 00, 04 and 4x.
If indeed there's a hardware problem, is it worth finding a diagnostics floppy to execute w/ ROM FF, or should I start replacing the memory chips?
TIA