Thanks for the reply. Alain. Hear the strangest thing. Whenever I touch pin 7 of IC107 or pin 9 on IC207 the both sine waves come up perfectly. From experience I know this could be caused by an open ground. I connected a 47uf cap between D13 and R24, the sine wave came up and the amp worked good for hours.
Also whenever I apply cold spray any where close to Ic 107 the amp works fine. I obviously replaced the 2 Lm339 ICs.
CORRECTION: IT SHOULD READ BETWEEN D13 AND R24 AND GROUND.
This capacitor seems to switch the'sleep mode' to the 'wake up mode'
Im not too big on theory. Joust, I believe someone like you can explain why did the capacitor do the 'trick'
Ch2 odepp goes off at frequencies between 200hz and 800hz. This seems to be a separate problem though.