Apple III Troubleshooting and Repair

[Griffo]

BTW, it does the exact same thing without the CPU installed, so I don't think that's even running. I think the screen is black if I remove the ROMs.

I'm having the exact same issue - did you ever resolve it?

 

[VERAULT]

Board flex and socket/seat issues is usually the culprit. These things run extremely tempermental even when they "work"...

 

[BeniBluemchen]

After a few years, i have now a similiar issue.

As you can See on the Monitor the Video SRAM is Not reseted by CPU. I can use the Keyboard reset but it doesnt reset the Video RAM.

No Progress in it ?

 

[BeniBluemchen]

I have also noticed a very asymmetric real time clock on the CPU - 4x times longer high than low.

 

[beer20574]

Yeah the tube or something in my old CRT would make the screen go pink with white lines across the picture. A good slap would always reset it but the intervals got worse. Initially it was once every few days, then it got to needing a slap every 15 or so minutes.

 

[wottle]

I have also noticed a very asymmetric real time clock on the CPU - 4x times longer high than low.

Were you able to figure out the issue? I have a similar issue with my ///.