24 Jul
2013
24 Jul
'13
3:13 p.m.
-----Oorspronkelijk bericht-----
Van: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org]
Namens Rik Bos
Verzonden: woensdag 24 juli 2013 14:01
Aan: 'General Discussion: On-Topic and Off-Topic Posts'
Onderwerp: RE: HP 7906 spindle motor repair ??
time.
-----Oorspronkelijk bericht-----
Van: cctalk-bounces at classiccmp.org
[mailto:cctalk-bounces at classiccmp.org]
Namens Christian Corti
Verzonden: woensdag 24 juli 2013 12:43
Aan: General Discussion: On-Topic and Off-Topic Posts
Onderwerp: RE: HP 7906 spindle motor repair ??
On Wed, 24 Jul 2013, Rik Bos wrote:
after many
Thanks for the advice, why should it be different
?
Well, our drives made terrible noises when they spun up the first time years. My first thought was bad bearings (singing
and screaking like
old
HDDs),
but otherwise the drives worked fine, so I just
ignored (and somehow
even enjoyed ;-)) the noise. But the noise went away after a few hours
of
running, so I
> think the bearings (the grease or
> whatever) have "recovered" from sitting there unused for such a long
But it may be
possible that you really have bad bearings or a bad motor.
DSU is disc service unit as referred in the service manual.
http://www.hpmuseum.net/display_item.php?hw=743
One disc had a head crach, I've to look in that I have a set of spare Removing the coil connection and a little
tampering with the control
lines should keep the drive on.
But you of cause do own a DSU unit, which makes live a lot easier...
Am I right ?
What is a DSU unit? But no, I used the drive normally, attached to out
HP1000/2100 system.
Christian The other one makes a lot of noise heads inspects ok,
I'm afraid the
vibration
caused by the spindle motor causes a head crash.
So I'm going to let it run with the heads retracted, by fooling the
control
board
and see what's happening.
Did you take other precautions to prevent the disc from ruining itself?
-Rik
Small update I tied the /RS line (Run spindle) to the ground, I also
disconnected the voice coil so the heads stay retracted for the moment.
The /RS line comes from U65 (LS04) pin2 on the control board, I removed the
pin form the hole and made a wire to ground.
The disc is running at the moment, and screaming and making other noises.
I will let it run for a time and look what's happening.
Tomorrow I'll look at the earth strip.
-Rik