Original well scanned manual. Got the job done. Microwave problem found & corrected. For $5 and a new magnitron from ebay, it was a cheap and good the first shot fix. Electrical schematics allowed me to mage sure every thing else was ok before cutting and order for parts. Hard to live without.
Text excerpt from page 87 (click to view)
TROUBLESHOOTING GUIDE
THE AUDIO CAN NOT RECORD
NO Is bias level at L101 OK? YES
In startinAg recording, is there sine wave at pin 11 of IC101? YES
NO
Check POWER BLOCK and voltage of base of Q103.
Check disconnection and short of L101.
Is there audio signal at pin 76, 78 and 80 of IC101? YES
NO
Check IC701 and the circuit from TUNER or audio input jack to IC701 .