IIgs Bad onboard ram

[Aaron707]

Greetings,

My brother picked up an Apple IIgs for me from the thrift store yesterday. I am getting an error: system bad: 02010400 when I run the self test by holding command+option during boot.

From what I can determine, this is a ram error. I removed the add-in ram card for now and re-ran the test with the same result. Does this error show ram chip bank 01 is bad?

If so, would this be the chip "UM1" on the mainboard? And last, are these the correct replacement chips: http://www.jameco.com/z/41464-10-Major-Brands-64KX4-100NS-HY53C464S-10-DIP-18-DRAM_41574.html

Thanks!

 

[Aaron707]

Update:

 I ordered the DRAM chips in my previous post. It turns out UM1 was NOT bad. After replacing all four "standard" ram chips on the IIgs mainboard the error still appeared and programs still would not boot without crashing. As I learned recently: those four chips are BANK 0. BANK 1 is the "Fast Ram" (UH13,UH14,UH15,UH16). After replacing the four chips in BANK 1 the system passed all tests and is working correctly now. I hope someone finds this information useful. Another Apple II saved from the landfill!

 

[ScutBoy]

Nice work! Gotta save as many as we can

 

[NJRoadfan]

The "standard" chips, which run at 1Mhz, are banks E0 and E1. The fast RAM is back 00 and 01.