Mesa DC-3 Low Volume on Rhythm Channel

[dorrisant]

I have tried a lot of things here.

All new known-good preamp tubes.
Cleaned tube sockets with Deoxit.
Reflowed solder joints at sockets.
Checked relays.
Checked LDRs.
Jumped out effects loop.
Footswitch functions properly.
EQ switches fine.
Lead channel seems fine.

Seems like the relays are not getting proper voltage. It acts like the LDRs are working.
Amp stethoscope gives good signal at the master volume pots.

Anyone have the Switching Matrix voltages?
Any ideas?

Thanks in advance.
Tony

[dorrisant]

Figured it out...

It was one of the 4n33 optocouplers.

Changed all three while I was in there.

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