The Fan was never hooked to the cpu?
I would say the cpu burned up a long time ago?
Also when power supplys blow capicitors, you can get a surge as someone noted earlier. This surge can flash the rom. Since when you do it on purpose you are sending 5 or 12 volts to the rom for a flash.
If this mb has an ISA slot, An old ISA video card can be used to boot up,since ISA cards have there own bios. This way you could see if it posts at all.However no floppy means it probably flashed the boot block on the bios.
If you really loved this computer, you could replace the bios rom chip, or do a hot swap trick if its not soldered on. Last but not least, pulling out the coin battery(if there is one, for 15 min) then put it back in can reset things.
