Sound degradation problem on the right side! - SOLVED -

[Chris Simon]

You're very welcome. I have seen more issues with the digital side of things on the '24 card. In particular, the switching of the four Monitor Cut buttons. Check that the voltage on pin  52 (RF Cut) matches the voltage on pin 53 (LF Cut). If it does, I might suspect T3 or TR7 being at fault. Also, if you see any component leads on the underside of the board that are encased in black rubber tubing, check for corrosion around the leads and the board traces underneath. I've recently been dealing with this corrosion on one of our consoles (see photo).

[Franz]

Hey Chris, problem solved! The oxide had affected the capacitor pin C7 and the 100k ohm resistor did not work well by passing all the current that did not even make the RF cut work. Cleaned and changed the resistor, everything worked again. Thanks!

[Chris Simon]

You're very welcome. Generally, when I see any of that corrosion, I'll replace the tubing and components right away. I've seen this not just in the 651 cards, but also the '242 EQ cards.