Troubleshooting an IBM 5155 - (portable personal computer)

From: Kelly Leavitt <CCTalk_at_catcorner.org>
Date: Sat Jan 15 20:04:03 2005

> From: Fred Cisin [mailto:cisin_at_xenosoft.com]
> Sent: Saturday, January 15, 2005 2:59 PM
>
> > Now, by disassembling and cleaning the B: drive, I was able
> > to get the machine booting off this drive (cabled as A:).
> > However, the same cleaning procedure on the A: drive did
> > not allow it to boot. I still have to clean
> > the heads. Maybe that'll make a difference. If not, I think
> > I may have other Qume drives without the IBM monniker on
> > them that I can swap the bezels with. I just have to dig
> > through the cabinent and see what'll fit.
>
> THe early, original Qumetrak 142 drives have my nomination
> for the second
> to worst drive ever, coming in right after the early versions
> of the BASF 2/3 height drives.
> The Qume drive was SO slow, that PC-DOS 2.10 had to extend
> the times to prevent timeouts on normal disk I/O.

Well, I just went through the "closet-o-drives" and I don't have any other
Qumes laying around. Furthermore, the DS/DD drives I do have the card edge
connector on the wrong side. The included cable is not long enough to plug
one of these in and leave the one working original drive. Does anyone have
the service manual online for this drive? I would really like to get the
Qume drive working, but don't know where to go next. I guess I could swap
the boards between the two units, but that'll only tell me if it is
electronic or electro-mechanical.

Other than that, any suggestions for figuring out if it is alignment, broken
sensor, or something electrical?

Here is what's happening with this drive:
The computer goes through it's mem-test, then advances the head. The head
retracts, then the system immediately dumps to cassette basic. It doesn't
even seek again.

I don't have an oscilloscope handy, and wouldn't know exactly what to look
for anyway.

Thanks for any help.

Kelly
Received on Sat Jan 15 2005 - 20:04:03 GMT