Static in left channel on vintage Marantz 2240 Receiver

[Beanie]

I finally got the part that was faltering on my Marantz to kick out.
The reason the 2240 got shelved a few years back was because the left
channel cut out. I pulled it out this summer, gave it a good
cleaning, got rid of the noise on the controls, and set it as my main
reciever (replacing a low-end 1997 Kenwood). However, I knew that the
fact that it was working was too good to be true--and I was right.
Before today, I would experience small amounts (about 10 seconds or
so) of a scratchy noise every 6 hours or so that the receiver was
operating. Now, there is almost constant static. It's always in the
left channel, it's unresponsive to the balance setting (it still
exists if I set it to extreme right), it occurs on the main speakers,
remote speakers, and the headphones, and it's enough to cause the
Marantz's speaker protection relay to kick in. I'm assuming that the
problem is somewhere in the left channel amplifier--but I'd like
suggestions for a starting point. (I do have a schematic handy--but
I'd need to find a scanner to get it online.)

Thanks in advance,

--Chris

 

[GregS]

Determine if its just the power amp or preamp. Disconnect the preout / amp in,
and listen. Sounds like the amp from your details.

 

[Jeff]

No, most headphone output is from the main amp
dropped by resistors only.
Jeff