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: If you only have the classic through-hole caps and you don't want to wait for the SMD parts 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 electrolytic or polymer SMD caps of the appropriate diameter and matching or slightly higher capacity/voltage rating.

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