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 20 (click to view)
MCM 21T1
2-7. SERVICE POSITION
CAUTION : SHORT
D,G boards Rear shield
* If the claw is hooked,
opening and closing the board is impossible. Do not try to do it by force.
D board (Refer to 2-2.)
A board (Refer to 2-4.)
* If the claw is hooked,
opening and closing the board is impossible. Do not try to do it by force. G board (Refer to 2-3.)