Repairing old 3.5" Floppy drive

Discussion about old PC hardware.

Repairing old 3.5" Floppy drive

Postby Vaudane » 2018-11-10 @ 14:47

Howdy all,

In my restoration of my old Compaq Deskpro 386s, one problem that has reared is head is the original floppy drive has the dreaded "insert system disk or disk error" problem.

I know what you'll want to say, It already has a replacement floppy drive in it for general use, but I'm a purist and I want to repair the original.

I've cleaned it with spray-IPA, I've wiped down the read heads with IPA/lint-free cloth. I've checked the CE interface, I've replaced the CE cable (turns out one of the wires had been severed so that explains part of the problem). All bits of the drive appear to click into place properly when inserting a disk.

The 5.25" drive and the replacement 3.25" drive on the new ribbon cable work fine so it's definitely a drive issue.

So short of borrowing a 'scope from work and trying to check each chip individually, I'm out of ideas.

Edit: attached pic
floppy-r.jpg
User avatar
Vaudane
Newbie
 
Posts: 49
Joined: 2018-7-30 @ 14:47
Location: UK

Re: Repairing old 3.5" Floppy drive

Postby Intel486dx33 » 2018-11-10 @ 18:31

I usually just clean the heads with isopropyl alchohol and a q-tip. Then check the motor and gears. Make sure they are aligned properly and lube them up. Check and lube the eject mechanisms.
User avatar
Intel486dx33
Oldbie
 
Posts: 709
Joined: 2018-5-17 @ 01:17
Location: U.S.A.

Re: Repairing old 3.5" Floppy drive

Postby Vaudane » 2018-11-10 @ 23:27

Intel486dx33 wrote:I usually just clean the heads with isopropyl alchohol and a q-tip. Then check the motor and gears. Make sure they are aligned properly and lube them up. Check and lube the eject mechanisms.


Thats... actually half fixed it. I used Finish Line Ceramic Grease on the motor worm gear and it no longer reads a phantom disk.

Sadly it now says... nothing at all... it doesn't read any disk, and I cleaned the heads with IPA and a lint-free cloth (no q-tips to hand).

You mentioned alignment - how does one go around checking this moreso than visually?
User avatar
Vaudane
Newbie
 
Posts: 49
Joined: 2018-7-30 @ 14:47
Location: UK

Re: Repairing old 3.5" Floppy drive

Postby Vaudane » 2018-11-11 @ 03:43

So it would appear one of the wires connecting the bottom read/write head to the solder points on the ribbon wire has snapped.

This is going to be a more fiddly job than I anticipated...
User avatar
Vaudane
Newbie
 
Posts: 49
Joined: 2018-7-30 @ 14:47
Location: UK


Return to General Old Hardware

Who is online

Users browsing this forum: Google [Bot], Scraphoarder, yawetaG and 5 guests