Maybe this is linked to your problem with your timer running too fast.
No this is a different machine.. That problem was on the other one I put aside with the 3.2 HD problems.
This one is another one that I knew was having a problem with the external floppy drive.. It is a rev 6.3. But I now know the problem is more serious than a blown 8520 because it just smoked one of my Gotek drives.
I have an extra floppy drive assembly that has a floppy drive for DF0: and a Gotek for DF1: It is (was) a known good all around power supply and drive setup for testing only that I use. I moved the unit in this machine out, and plugged this one in because neither floppy on it would boot the computer.. lots of read write issues even for known good disks.
Well, plugged it in (and before someone says anything, yes I always double check cables etc), added power and at first everything appeared to be ok.. Got the kickstart screen and it say there for a good minute.... and then suddenly SMOKE came billowing out of the Gotek. Suffice it to say it's toast. It still actually shows the OLED function but plugging in a USB media now does not work. Dunno yet if I can repair it but that's low on the list as I had another one.
The floppy on my test rig does boot the machine fine however. So either the p/s or both floppies have an issue that came with this machine. For now I will keep the test rig in this until I get it working fully.
I have never seen something like this before.. it's like power fed back into the unit somehow... or it was a coincidence that something just happen to fail while plugged into this board, which has a bad external floppy port already.
I pulled the Gotek, installed another and so far, it appears to be ok in that regard, so I have no idea what caused that. But my test P/S/Floppy/Gotek is functional again at least. Now I need to figure out what the hell the problem is with this external port. I swapped 8520's so now I need to look deeper for a problem and will test the fusable links that Pat the Cat listed next..