Lisa floppy problems

From: Paul Grammens <pgrammen_at_sonic.net>
Date: Thu Sep 10 16:11:04 1998

At 12:27 PM 9/10/1998 -0700, you wrote:
>
>Hi folks,
>
>I'm having some problems with a floppy drive in a newly aquired Apple
>Lisa, and I'm hoping someone here will have some repair tips.
>When I first powered up the system, the floppy drive seemed to be
>working fine. I booted the system into MacWorks+ off of one of the
>ProFile drives, and was able to format, read, and write floppies with
>no problems. However, a few hours later, the floppy drive started
>making horrible "CLICK CLICK CLICK CLICK ..." noises, resulting in
>a wave of panic and fear :)
>
>I investigated, taking off the front cover of the Lisa to get a closer
>look at what was going on. It appears that the head assembly, which
>is moved back and forth by a spiral cam shaft, was all the way in the
>back-most position -- but for some reason, the drive didn't know it
>was all they way back, and the cam shaft kept turning, trying to push
>the head assembly back further. The "CLICK CLICK CLICK" was coming
>from the spiral cam shaft clicking the little driver arm on the head
>assembly as it spun around.
>

Hard to say for sure, but there is a sensor on the right side (viewed from
the front) that detects when the head gets to the end of its travel. Could
it be dirty? I think it uses LEDs and photo sensor to detect a plastic
piece passing between the emitter and sensor. I've seen behavior such as
you describe when solvent gets on the sensor. The most common problem with
this drive (assuming it is the same 400K drive used with the 128K and 500K
Macs) is that the grease turns to glue with age, gumming the eject
mechanism. Sounds like that is OK. Was it cleaned recently? If so, it may
just be solvent in the area of that sensor. I thought I'd ruined a couple
of drives in cleaning them, but after sitting for a while they stopped that
"click click click" you mentioned. If it is the same drive as the Mac
drives, you should be able to pick up a replacement for a dollar or two,
worst case. Good luck with it!
-Paul
Received on Thu Sep 10 1998 - 16:11:04 BST