8580 Floppy Troubleshooting Question (not capacitor-related)

[William Murray]

I just bought an 8580 and as expected, the floppy doesn't work. It's one of the type 3 25MHz planars and the drive is a MF355C-599MA. It turns on fine, but without a floppy drive I can't load a refdisk and use the machine. I replaced the capacitors on the floppy and nothing has changed. No significant corrosion either. The drive has absolutely no signs of life (no spindle spin, no head movement). When I got it, the 5V fuse was blown on the floppy connector. Later on, I accidentally blew the 12V fuse too while poking around with my multimeter (the drive was not plugged in then). However, even if I short the fuses to restore 5,12V power, the drive does nothing. Is it likely that whatever blew the 5V fuse probably killed one of the floppy's chips? When I bought the machine, it also had two dead hard drives (neither would spin up), and one of the drive's power connectors was shorted to ground. Maybe one of them caused the problem...