Weird RX02 problem

From: shoppa_classiccmp_at_trailing-edge.com <(shoppa_classiccmp_at_trailing-edge.com)>
Date: Tue Feb 15 16:09:39 2005

>After several failed tries, I finally tried formatting on drive 1 and it
>worked. Hmmm. Even though I'd opened the case last night to check for a
>loose cable (and didn't find one) I opened up and looked again. I thought
>maybe I jostled something because every 5 disks or so I have to open the
>cover to clean the heads (I can't find any of my 8" drive cleaning kits).
>Anyway, I checked all the mechanical bits and reseated the cable to drive
>0 and then it started working again.
>
>Has anyone ever had this experience before?

Sounds like you weren't getting the "drive ready" signal from drive 0.
Maybe it was a problem on the 50-pin floppy bus messing everything up
for a while.

On generic 8" floppy drives (e.g. Shugart SA801), "drive ready" comes
from a one-shot triggered by the LED/photodetector that shines through
the index hole. Ambient light can mess up thresholds, leading to
some bizarre circumstances like "it works with the cover on but not with
the cover off", "it works with the cover off but not with the cover on",
"it works fine until 4PM in the afternoon" (which happens to be when
the sun shites through the window into the drive box, etc.)

Mechanical alignment of the index LED/detector can be a little out of
whack sometimes. There's also a pot on the PCB for setting sensitivity,
IIRC.

Someone else mentioned steppers that don't want to step... this is
a problem on many of my Shugart 801's recently. It's basically just
surface rust.

Tim.
Received on Tue Feb 15 2005 - 16:09:39 GMT