[comp.sys.ibm.pc.hardware] Hard drive not spinning up

userNQNF@mts.ucs.UAlberta.CA (Dale A. Ulan) (11/11/90)

I've got a Miniscribe 3053 (44 meg 28ms voice coil positioning).
A while back I was having problems with the drive not spinning
up. A gentle tap (and I mean gentle) on the analog board would
get it going. I removed the IDC connector (attached to a small
ribbon cable and going to the middle of the hard drive, where
the motor should be), used some rubbing alcohol on the pins and
connectors to clean them up a bit, then put the connector back
on and it worked. This is the course of action I would first
suggest. My best guess is that there is a loose connection on
one of the phases on the platter motor. What I mean is that the
platter motor is no more than a 3 or 4 phase motor electronically
controlled. If one phase is dead, then it won't start, but once
spinning, it will continue to run fine. This is what makes a
brushless DC motor. The problem is most likely in a connection,
or in a part of the board. I would not open up the hard drive
case at all-- ever. Unless the drive crashed and I wanted to
see what was inside.
Oh, the motor is controlled by a servo-feedback system of some
sort, so the speed shouldn't change much, even though a quarter
or a third of the motor isn't running properly.
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My opinions may or may not be correct, and may or may not
reflect the opinions of this University.
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