Hello,

My IBM PS/2 model 30 (8086 cpu) has a 3.5" 720k floppy drive which doesn't read any disks.
Since I have a spare 720k floppy drive which works fine, I'm fairly sure that the floppy disk/controller/rest of pc are ok.

Googling brings up the following topics:
- clean heads (ok, did that)
- electrolytic caps that might need replacement: I removed all of them (3x 47uF/16V, 1x10uF/16V) and fitted new ones. No difference. I checked the desoldered ones, they are all in spec 🙁

The PS/2 model 30 doesn't seem to do a 'full' floppy drive seek: I just selects the drive (motor spins) and moves the head a single track back and forth. Most PCs I've seen move the head over all tracks.
Is this behaviour normal for a PS/2 mod 30?

Anyway: the working floppy moves the head at power up just a bit, the broken floppy doesn't move it at all.
Is there any way I could check the floppy drive?

The ROM Basic comes up, but I haven't figured out how to access the floppy from there.

Any troubleshooting tips?

--eax