Quote from: Tassieviking on November 24, 2023, 01:53:47 AMIf I have the facts right, the following happens:
1.Distortion channel stops working but amplifier still works but only on the normal channel.
2. When this happens both the normal and distortion LED's go out.
When you want to use the distortion channel you have to pull the Treble knob out, or use the foot switch.
The relay operates and switches the amp to the distortion channel, the relay determines the channel that is used.
power is lost to both the LED's and the relay when fault appears, pointing to the 1k5 1w resistor to me.
I would suspect that the power to the relay goes out, possibly a bad solder joint or a faulty 1k5 1W resistor that goes to the relay from the +58v rail.
It is strange that you are worried about that power resistor that is also 1k5 that is dropping all that powder, there are only 2x 1k5 resistors on that schematic that I can see and they should be 1 watt.
In a previous post the same component was questioned.
I think you should try to trace where the 1k5 resistor is that feeds the relay, and then replace it. also re-flow all the solder joints in that part of the circuit.
If you take the PCB out and take some photos of the bottom tracks and the top of the PCB we might be able to help you trace it better.
Inspect the solder joints with a jewelers loupe or strong magnifying glass and you might see the problem.
I have 3 jewelers loupes I use for that job, 10x, 20x, 30x magnification I got from E-bay for dirt cheap. Best buy I ever did.
Edit: I think the red and green LED might be swapped around in the schematic as well.
Quote from: Tassieviking on November 24, 2023, 01:53:47 AMIt is strange that you are worried about that power resistor that is also 1k5 that is dropping all that powder, there are only 2x 1k5 resistors on that schematic that I can see and they should be 1 watt.I may have missed it, but I don't think he mentioned a value for the cement resistor?