Peavey Musician Mark III series 400g power loss

[ajsnjs]

Hoping someone has a quick and easy fix for my Peavey 400G...
When I turn the amp on, it works fine for approximately 45 seconds (all inputs work and output sound fine). After 45 seconds the power LED indicator on the front slowly dims to "off", the amp begins to hum, and all sound/music (except humming) is completely gone. If I turn the amp off for a few minutes it will work again, but only for about 45 seconds. Any help is appriciated. Thank You.

[Enzo]

Most likely you have a failed low voltage power supply, probably the +15vDC.

Look for the +15 and -15 supplies. There are a couple of three-terminal regulators on the power amp next to the speaker wire connections. Check their solder and general condition. You also could have lost the filter cap for one or both those supplies. Those caps are right next to the regulators.