So new problem. I seem to have really bad luck with these machines. I finally found a 68040 board, but I'm having no luck booting with it. The machine starts to a scrambled screen and the red LED on the board is flashing 3 times fast then 1 time slow. I replaced the caps, but I get the same symptoms. I also replaced the RAM and the CPU with no change. Does anyone have some suggestions? Is there a way to read an error code based on how the LED blinks?
I just found the following in an old newsgroup posting:
Five flashes in a row on the magic EKG LED indicates that the ROM
memory probe didn't find any (usable) DRAM. The ROM code is testing
the first 8 Kbytes of each bank of memory looking for a place to put
the ROM stack. In your case, it didn't find any. I'd examine the DRAM
sockets VERY carefully for broken/bent tines, and for cold solder or
flexure breakdowns. One pin not making contact is all it takes. Also
look arount the base of the memory controller (That big ole Fujitsu
chip on a 25 MHz machine). The freeze spray treatment Bruce mentioned
might help.
Just for fun, here are the EKG blinky light flash counts for assorted
failures:
1,2 ROM CRC check failures
3 Bad VRAM
4 Bad NVRAM (The NVRAM store in the clock chip)
5 No usable DRAM
So it looks like the vram may be bad.
Finally got around to replacing the VRAM chips this evening. Unfortunately same condition. :(