Repair of PS/2 8580 1.44 MB FDD

Created by Al Savage (original HERE). Modified by Major Tom.

Drive parameters:

P/N 90X6766, FRU P/N 72X8523, EC No. A58560, Date: Aug-89
Mitsubishi, Model: MF355W-99M3

When I went to to start up my 8580s, I found that all three of my floppy disk drives would not read diskettes.  Two of them are manufactured by Mitsubishi.  Before shelving them, I decided to pull off the covers and poke about.  I found several surface mount electrolytic capacitors that were either open or had very high ESR.

I successfully repaired both units by replacing the capacitors indicated.  The third unit is manufactured by  Alps, and I haven't looked at it (yet).

Exterior top view of Mitsubishi 1.44mb FDD

Part Label of Mitsubishi 1.44mb FDD

Locations of bad caps

Repaired unit No. 1

Repaired unit No. 2

Ed. Tom: Eh, if a through-hole radial caps are the only type you have, and you don't want to wait for the SMD caps to arrive, then sure, go for it! (it looks ugly, but it will work no problem) Otherwise I would suggest getting the proper replacement - a set of SMD caps with the correct diameter - and matching or slightly higher capacity and voltage rating!

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