I left it on overnight ... and now it won't boot - Commodore 2031/1541 repair

I accidentally left my Commodore 2031 disk drive on overnight, and now it won’t boot. Watch as I fumble around and eventually manage to repair it.

I left it on overnight … and now it won’t boot - Commodore 2031/1541 repair - floppies rock ep18

In this episode, I take another look at my 2031 IEEE-488 disk drive, in which I rewound the spindle motor tachometer in a previous episode. This time around the drive won’t even boot, because I left it on overnight, and presumably a component failed due to the heat. In the process of fixing the drive you’ll even see me make the problem worse than it was, before fixing it.

Timestamps

00:00 Intro
01:27 Symptoms
02:06 2031 conversion from 1541
03:10 Theory of operation
04:41 Schematic
06:44 Initial diagnosis
13:00 Swapping chips between drives
24:10 It verks (sort of)
25:30 Broken ROMs?!
28:19 Diagnosing ROM failures
29:10 Wrap-up

Problems:

The static RAM chip (TMM2016) had failed. I replaced it
While working on the drive I broke my 2031 ROMs, due to a poor design of my ROM replacement boards. I resoldered the damaged parts.

You can find the other videos about my 2031 disk drives here: https://www.youtube.com/playlist?list=PLXs34HaWLi133kZODssQy6rLJFXWRkaVQ