First post, by keenerb
I've picked up a Sensation II in excellent physical condition, basically looks brand new on the inside and very good on outside.
Has a DX2/66 overdrive installed, what looks like 8mb of memory, and the factory hard drive/expansion cards.
The problem is that there is no POST at all when I apply power. The CD-ROM and hard drive power up and self-test, there is no beep or floppy seek.
I verified that the PSU is supplying 5v and 12v (and -5v). I uninstalled all expansion cards and ribbon connectors. I've tried switching back to the on-board CPU (from the Overdrive processor).
I have packed away all my ISA VGA cards, but disabling on-board VGA didn't change behaviour at all.
Some fairly high-quality photos of the motherboard with all cards removed is at https://imgur.com/a/XtY53jq I see nothing that looks remotely suspicious here.
I've verified that the voltages supplied to the ISA slots and to the BIOS are correct. The BIOS is an EPROM, possibly it has been corrupted, I pulled the chip and dumped the ROM images, they are attached below.
I just moved, so once I find my NICE multimeter I'll see if the ISA CLK signal is correct. The dumped BIOS itself boots to a "Default loaded, press F2 to enter setup" prompt so it's at least MOSTLY correct.
