Behringer PMX518M output problems

[tonepumpamps]

Hello,
I'm working on a Behringer Europower PMX518M. there was no output when the customer brought it to me & I found a bad output transistor. I replaced both the PNP and NPN output transistors and what I have now is a distorted output. When I scope it it gives me a sawtooth waveform.
Anybody have any experience with behringer stuff?
Any help would be appreciated!
Thanks,
Scott

[wbegg]

My advice would be to toss it in the trash. Behringers are terrible to work on, and not much support from the mother company.

[Enzo]

Welcome to the forum, both of you.

wbegg, come on, that's not very helpful. A guy's amp is a guys amp, and like it or not, he probably wants it to work.

If there is a sawtooth on the output, look to the power supply. I forget what voltages it runs on, but let's say +/-35v for now. Are both polarity supplies more or less the same voltage? Are both relatively free of ripple? And same for the +/-15v supplies for the op amps. Are both up and clean?

Seems to me on that one I had to remove a couple of vertical power resistors to get at the screws for the power transistors. Either of them open?