writes:

On Feb 8, 11:49*am, "Arfa Daily" wrote:
wrote in message

...

My Sega CD, which uses the KSS-240a laser assembly, makes a spine
chilling sound when it gets warm.. *I believe it to be a cogwheel is
expanding when it warms up..

http://www.youtube.com/watch?v=U55FF7NLgn4

Any ideas on how to actually fix this? *The system gets no hotter than
it normally does...

I think that it is highly unlikely that anything is happening to the size of
any gear wheels. The (very brief) sound that can be heard on your clip,
sounds like the motor pinion slipping against the intermediate drive gear.
On a typical mech that uses any of the KSS series lasers, the most common
cause of this is bad contacts on the laser 'home' switch, normally located
on the spindle / sled motor connection board, right underneath the
turntable. When the contacts don't make very well, the laser homes as
normal, but no signal is generated when it gets there, to tell the system
control micro to shut off the drive to the motor, so it keeps running, and
the gears slip against one another. After a while, the vibration caused by
this often gets the switch contacts to make again briefly, which then causes
the drive to be cut. My first move would be to clean the switch.

Arfa

An update: I watched the laser move, and when it screeches, it's not
even near the home switch.. The motor spins, and the cogwheel does
move, but misses on the other gear (it never slips on the sled)...

There's a decent amount of play, because if I manually turn the
cogwheel, it does sometime miss too..

Do you need to find out why there's free play. There may be enough
free play for it slip or jump gears if something is binding, but not
otherwise. Does the sled move freely on the rails?

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