MTX Thunder Elite 404

[Perry Babin]

Is it possible that the square wave is the badly clipped sine wave?

Do the inputs to the LM339s pulse with no outputs in the circuit?

 

[Dr Zeus]

I cannot be sure about the signal I was seeing at the outputs. It happens so quickly usually all I see on my scope is a random flash-change off flat-line.

With the outputs removed from the amp everything still power cycles. I've got the outputs installed right now but will look at removing them if nothing else.

 

[kev79]

How did you make out on this amp. what did you find . i have a simalar problem.

 

[Dr Zeus]

Kev79,

I actually never fixed this one. I still have it in my posession though. I had verified with another MTX that this one's pre-amp board was in good condition. In one of the previous posts from Perry, I had taken his advice and removed Q102 with little effect.