strange amp problem

[feelander]

i have an ancient soundstream amp that only outputs static on channels 3 and 4. funny thing is the output is fine when in bridged mono mode - the static only occurs when in stereo modes. any ideas of what i should check out?

 

[TO-3]

i have an ancient soundstream amp that only outputs static on channels 3 and 4. funny thing is the output is fine when in bridged mono mode - the static only occurs when in stereo modes. any ideas of what i should check out?

Pull out the board and look for cold-solder joints. It may be a poor ground.