Thanks you very much for this "hard to find" service manual.
Will help a lot in repairing this receiver.
Text excerpt from page 3 (click to view)
KRF-V5020/V6020/V7020/VR-305/306/355
DISASSEMBLY FOR REPAIR
1 x2
2 x2 2 x2 3 x2
4
4
1. Remove the 8 screws (1,2,3), remove the rear panel. 2. Connect the GND of the rear panel and the chassis, the GND of the mounting hardware and the chassis with 2 alligators clip (4)