This PA repair, a Pro Sound1000, was brought to me with a couple of reasonably common symptoms. One channel was producing no output, the other channel was very quiet. To be honest I’m surprised that the internal fuses hadn’t blown. The symptoms pointed towards what is probably the most common problem with solid state PA repairs – several of the output devices were short circuit in one channel. This affects the shared supply rails of the power amp, which probably caused the effects in the other channel. I replaced the transistors from the faulty channel and both channels ran fine.
Whilst fixing the amp, I noticed that the reservoir capacitors were leaking, so these were replaced as a precautionary measure to prevent future damage.
If you have a PA repair that needs some attention, please get in touch.