Report "The amp has an intermittend problem. The sound just disappears, but you can hear a noise coming from the PC board that sounds like a relay that makes-and-breaks repeatedly. If I connect it to the power amp, it works sometimes (even for a few days), but then the problem comes back. You can see some brownish patches on the PC board (probably due to heat), and I cleaned these with spirits. Can you offer any advice on what to look for ?? Thanks. Hannes Fourie"