This document is just what I was looking for, it´s very useful, it contains adjustment procedures for the final stage of the power amp and also
has a complete wiring diagram and description of the main semiconductors used in the design.
Text excerpt from page 19 (click to view)
2. Servo Circuit
A. Unstable Video in PB Mode.
Does the on screen noise level change periodically?
YES
Do CTL pulses appear at IC501 pin 97?
YES NO
Does the CFG divideIC501 waveform appear at pin 87?
YES
Is the height of the CTL Head adjusted correctly?
NO
Do the CTL pulses move when TRK is operated?
YES NO
Adjust the CTL Head.
Does the Video Envelope waveform appear at IC501 Pin 9?
YES NO