Egnater TM4100 mystery gremlins need help please??

[glasspak73]

I just bought a used Egnater Tourmaster 4100 head and it has problems.1) channel 1 overdrive has barely any audio passing through it.i can hear the eq and gain and volume works for this channel but it sounds like its shorted out enough to barley let sound go through. 2)I noticed that the tube buffered effects loop only lets half the audio through it with send and return knobs on back maxed out on 10 both. 3) I noticed with master volume up half way and all 4 channel volumes turned to zero if I tap the front or sides of the amp with my finger it makes a tink sound(through the audio path out of the speaker) wich I think is microphonic tubes somewhere. Does anyone on here have any info about this amp? I really need the schematic if possible.

[nostradoomus]

I would retube/bias it and see how many problems persist. The weak sound is definitely a symptom of a bad power tube.

Let the tubes warm up for a bit and lightly tap each tube with a pencil. Its normal for them to make a slight sound but a microphonic or bad one will be very obvious.

[glasspak73]

The weak signal on overdrive 1 channel is in the preamp section.I found the schematic online from digi2t so now I think I know why that channel is dead.possibly bad volume pot or just bad solder joints.i'm going to take it apart this weekend and see what I can find.I'll keep posting my finds on here maybe it will help other tourmaster owners.Thank you nostradoomus for the info