Hi,

I have another bit of hardware which needs (hopefully) just a bit of persuation to get back to life.

A chaintek PCI/ISA motherboard of the make 486SPM M102.a is my latest troublemaker that keeps me up at night.
It appears to be dead in the sense that there is no video output and no pc-speaker beeps.

Things tried so far:
Testet with known good:
- ISA graphics card, PCI graphics card,
- multiple different PS2 RAM modules 4MB, 8MB, 16MB
- reseated TAG RAM and L2 cache, used different L2 cache and TAG chips, also different sizes, also just BANK0 and BANK0+1
- Reseated CPU multiple times to hopefully remove corrosion in the socket if that is the culprit
- tried AMD DX2 80 MHZ, AMD x5 133MHZ, and also Intel DX2 66 to check if 5V CPUs work at least
No signs of life, BUT the chips get slightly warm when powered up measured with an infrared thermometer... so there is power present.

There is one hint though:
When I put it back in its box because it upsets me too much and at one point I get it out of the box to try again, there is this suspicious burnt silicon smell coming out of the box but there is no signs of damage at all on the mainboard.
It is in almost pristine condition.
The smell oritinates from between the two isa slots adjacent to the BIOS chip. There is two small to92 transistors.. but optically they seem perfectly fine and when powered on they also don't get hot or anything.

Maybe someone on this forum had already some similar experience?

Greetings

audiocrush

*edit*
after a lot of messing around I solved the problem
After the ISA/PCI Diagnose card arrived I checked it, and it just gave weird and garbled results on the display, putting out error codes that are not valid for award bios
I changed the ram again from a known good 4MB FPM Stick (board kept silent, didn't show anything on the screen) to a known good 4MB EDO stick and voilla it started beeping like crazy
Then I changed it to another EDO stick also 4MB and the board went silent again...
I used another known good FPM stick, the board stayed silent
And then I used another 8MB FPM stick and voila I got a perfectly fine working Mainboard agian...
So what's the deal?
Has anyone experienced such a picky board before?
I don't know the difference between the working and the non working FPM sticks because on 3 other boards I have they all work perfectly fine.
Hope this helps other people 😀