First post, by Bjorn
I've had one of these notorious boards for a while, (one with REAL cache!) and tinkered with it on and off. Can't seem to get it to do anything, but somehow I can't seem to give up on it.
No POST, no beeps, not even any POST codes on my analyzer card. Heck, not even a clock signal! (This analyzer works perfectly on other boards BTW. I know there's some dodgy ones about)
I'm measuring 12v and 5v in all the right spots on the ISA and PCI buses though.
I've swapped CPUs and memory and I've tried multiple video cards and every jumper configuration conceivable. I changed a couple of caps that I was vaguely dubious of, and I've pored over the traces for ages to see if I could spot any broken ones.
My best theory is that the BIOS chip is fried - I seem to recall when I dug it from the eWaste bin the chip was in backwards.
Also, it's a rebranded chip, and I'm not sure I've found an exact match in the xgecu database, but my xgpro always shows one pin (the write enable pin) to be faulty, no matter what chip I choose. And I spent a LONG time going through every chip that looked remotely like it could match. The ones that seemed to work best were 28C010 variants, and one 29F010.
That said, I still managed to dump the contents. It has recognizable headers and footers, but I can't tell if anything else is corrupted on it.
I've tried to replace the BIOS with two different chips - just what I had lying around. One SST29EE010, and a P28F020, and I've flashed them with every ROM dump for this board I could find online (I duplicated the data into the front and back half of the P28F020, because it is twice the size).
Nothing has worked.
I really don't know enough about eeproms, but I would have thought these should have been compatible. Could the M918 just be so picky with exact chips?
I feel like I'm barking up the wrong tree with the BIOS thing... surely I should at least get a clock signal?
Anyone got any ideas?
Rebranded BIOS chip (after peeling the AMIBIOS sticker off):
(The 486SX is just a swap-out to see if the CPU was faulty)