wrote in message
...
Mark Zacharias wrote:


They had a lot of shorted spindle motors on those...

this one looks like it's still spinning... It just doesn't play most of
the
discs.

Frank


Many times the motor is still the culprit, and the disc is having trouble
getting up to speed.

Try testing the motor with an analog VOM on Rx1 ohms range. Slowly rotate
the motor. The resistance will vary as the motor is turned, but should be
around 10 ohms on each 1/2 of it's rotation. Sometimes one or both halves
will be shorted or partially shorted. It is often possible to clear the
short.

You can spray cleaner/lubricant into the slits at the bottom of the motor,
aimed at the brushes, while turning the motor by hand. Use compressed air to
blow out debris and excess lubricant. Repeat til short cleared. Very
effective, fixed lots of cd motors this way over the years, only ever had
one re-do, and that one was in commercial use.

You can even connect a variable dc supply to the motor, run it at a given
speed, spray the cleaner at the brushes and really notice the motor "taking
off" when the short clears. Even without cleaner, if you run the motor at a
pretty high speed, the carbon will likely burn away at some point.The
brushes pick up the carbon from sparking, which shorts out eventually.
I_think_ a silicon based lubricant will prevent future carbonization.


Mark Z.