jon@jonlab.UUCP (Jon H. LaBadie) (09/17/90)
Months ago, I posted a note asking what might be wrong with
the floppy drive in my 3B1. I could read diskettes, mount
them, but not write them or format them.
No response came in at that time, and I have been living with
a borrowed 3B1 as a UUCP/archive partner.
Recently Boyd Ostroff:
Boyd Ostroff - Tech Director - Dept of Theatre - SUNY Oswego
Sys Admin - "The CallBoard" - (315) 947-6414 - 1200/2400 baud
ostroff@oswego.oswego.edu - cboard!ostroff@oswego.oswego.edu
posted a note describing a similar problem - AND HIS SOLUTION.
Turns out, his solution seems to also be my solution - dust had
occluded the light path for the write protect sensor making
every diskette seem to be write protected.
THANKS BOYD!!!!
-----------------------------------------------
This was only the third time I have opened the case of "jonlab".
And before I was done, it became the 4th, 5th, and 6th time.
Along the way, I encountered a few situations I would like to
pass along. Some of which our very esteemed and appreciated
colleagues - you know, lenny, thad, uncle john, and others;
might overlook as too trivial. They encounter them frequently.
1. As I only wanted to look at the floppy drive, I tried to follow the
FAQ notes on how to open the top of the case (at the seam above the
keyboard shelf. However, I was never able to get the case open at
this seam by poping the tabs with a screwdriver along the seam.
BTW, my case has only 2 locking tabs, not the 3 mentioned in FAQ.
I believe these tabs are meant to be unlachted from inside, after
the case is removed from the metal frame. Many gouges in the
plastic case caused by screwdriver pressure attest to this notion.
2. Removing the floppy drive was fairly straight forward (I could not
see the light path, and wanted more access). The only problems
were removing the power connector (tight as hell, wrongly suggesting
that some latch was holding it in) and how to support the top shield
in the tilted position while working on the screws below the shield
(still looking for this answer).
3. Some items to add to the FAQ if I didn't simply miss them.
a. When tilting up the metal cover above the mother board (the one
on which the drives and power supply are mounted), on my machine
it is necessary to disconnect the 10 pin video connecter (tight,
on the left side under the floppy drive) and the power supply
connections to the ON/OFF switch at the back of the case.
Mine were short enough to require disconnect, others may have
sufficient slack that this will not be necessary.
b. When reassembling the case, be careful to properly dress the
wires to the ON/OFF switch. When I finally got things OK,
my fan (yes, still the original 12V job) did not start. I
said Oh Shit, the well known fan failure problem. But it
was not. Simply, the wires to the switch were impeeding the
fan blade rotation. Make sure they do not go near the fan.
4. Working on the floppy drive was not as simple as Boyd's posting
implied. Yes, I am sure the dust-bunnies were there, but they could
not be seen. The light path was not observable without further
disassembly of MY drive. Boyd's might have been different. I had
to remove a printed curcuit board at the front left top part of the
drive. The LED's for write protect and rotation sync, are on this
board. This exposed no visable dust bunnies, but much dust around
the LED lens (recessed). I also wanted to try to remove any dust
from the photo receptor below the frame. This was not visible, but
there was a tiny hole in the frame for light from the LED to pass
and I simply probed with the toothpick through that hole.
5. Reinstalling the floppy drive was a problem. First, it was too far
back (the data connector hit the case), then, it was too far forward
(the top case hit the floppy drive). Finally, I aligned the floppy
drive with the HD shield. Turns out this is "SLIGHTLY" too far
back, but good enough for government work :-).
So, if you are having problems with writing, but not reading your
floppy drive, check out the obvious -- the write protect sensor.
WHY WASN'T IT OBVIOUS 4 MONTHS AGO?
Once again, thanks Boyd!
Jon
--
Jon LaBadie
{att, princeton, bcr, attmail!auxnj}!jonlab!jon