CDM-2 Radial Servo Whining Loudly in CD 150

Spent a bit of time messing around with a defective CD 150 I received, one of whose servos is whining loudly.  The player has a CDM-2 and there are a lot of variants of that, and heard there were some challenges during production of the CDM-2’s

First checked the disc height; due to wear, the disc height drops because of a small indentation where the spindle rests.

measuring with a test CD and within +/- 100 mV

If the player plays normally, the radial signal looks like this.

here in oscillation

then search in mountain CMD-2 service manuals

After reading the datasheet and other documents, I adjusted the resistor ( 3151 ) value on Pin 9 cLag.  A lower value 

After a few attempts, it worked; no more oscillating radial servo. The eye looks neat too.

We are going to keep an eye on it for a while.

Another problem is the wear of a small rubber stopper; it limits the minimum and maximum position of the swing arm. I suspect that if this small rubber stopper is missing, the swing arm moves too far towards the inside of the CD and sometimes just fails to find the TOC/lead-in track.