A501 Rev 6 no memory detected

[insanity213]

So I dug out an old A501 that I've had for years. I removed the leaky battery and the damage wasn't extensive at all. The RTC shows up but none of the RAM is being found. Amiga Test Kit 1.11 Memory diagnostics says "WARNING: Possible faulty SLOW RAM detected" and allows me to force a test. Every bank fails on the 1st test.

I've checked all the caps and resistors on the board and everything checks out. I removed the RAM chips, installed sockets and new chips but still no dice. I can't find a schematic, so I'm pretty much out of gas. Any idea what would cause all of the memory to not show up at all?

[cmorley]

Thw A501 schematic is in the back of the schematics for the A500. It's called "Cake" or something like that.

[insanity213]

Thanks for the tip, who ever reads the last page of a manual?

Anyway, I still can't figure out whats wrong with this thing. I broke down and bought a new memory expansion from AmigaKit.

[GadgetUK164]

If one bit is bad in one of the DRAM chips, it will register as none. If you use DiagROM or Logica, those should tell you which bit is at fault, you can then target the specific DRAM chip.

[8 Bit Dreams]

http://amigawiki.org/dnl/schematics/A500_R6.pdf
You'll find A501 schematic on the last page