[Max]

you're saying that F1=setup but when you press F1, nothing happens. Is that correct? That makes it pretty hard to reset your BIOS settings. If you can, try another keyboard and see what happens.

if you get all this sorted and your machine starts to boot again, it might be worthwhile checking your memory. there is a tool out there called memchecker (or something close to that). you copy it to a floppy and then boot from that. it will run a bunch of memory checks to see if you have any problems. it's a free tool.

you also mentioned a broken clamp. get that checked out. is there any chance that your CPU is not seated properly? I had a broken motherboard / CPU combo that I gave to a friend of mine years ago. Turns out it was fine, the CPU just wasn't seated properly.