Sunn Beta Lead Input Jack unresponsive

[phreshphrankie]

So I recently swooped a Beta Lead 4x10 amp off of craigslist for 40 dollars from an old guy. The amp was said to have cut out mid-way during playing and now when the input jack is plugged in, the green and the red light does not come on, however, the amp powers up fine. When the input was bypassed by another amp, the sound coming from the speakers seemed to "sag" or start off loud and then decrease in volume when holding a note. I realize I am going to have to take it to someone who knows more than me, but does anyone have any ideas what may have gone wrong? Any similar situations? Should I call it quits and turn the amp into a mini fridge? Let me know.

[BassHog]

Generally input problems on Beta amps are caused by defective CMOS chips in the input and muting circuits. These also control the green and red lights on the front.
Not really a hard fix for someone who knows how to troubleshoot CMOS logic but depending on the chip they can sometimes be hard to find replacements for.