"Mike WB2MEP" wrote in message
...
On Tuesday, August 21, 2012 12:43:04 PM UTC-4, William Sommerwerck wrote:
A weak laser is a major cause of tracking problems. If cleaning the laser
optics doesn't fix the problem, you might need to look for a replacement
optical system, or a complete drive mechanism.

I've already tried two new laser pickups, and a replacement subassembly
containing the pickup, spindle & sled motors, with only slight changes in
performance. (I've had two spindle motor failures between the two machines
I have.) I also took the complete drive assembly from an identical working
player and installed it in this one and still have the same problems.

That's why I'm looking for a service menu in order to adjust the servo
gains/offsets. The older players had pots for this.

Mike


I think I would look at power supply issues - high frequency ripple,
regulation issues, etc.

This is extremely common on modern players.

No reason the servo board would have gone so far out of adjustment.

Mark Z.