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

This sounds like a better theory than mine. lol

The sound seems to more occur when the Sega CD stops an audio track
and goes to read data, so I guess it needs to return home to read the
TOC to find the data it wants.

Thing is, it happens ONLY when warm. When the machine is cold, it
never has this issue.

I'll give it a cleaning, though it's hard to get to that home switch
(i know where it is).. Hopefully getting the assembly out will be
easier than I fear..