Yamaha P7000S

[Analog Mike]

Anyone know anything about the protection circuit on this amp? I've got one that blew an output, but after replacing, it still won't light up.

[Twist]

Is that one of those big power amps? Do you have a schematic?

[Analog Mike]

Yes...this is one of those new rack mt amps with 1000 to 3500 watts, depending on who you read. It has a switching power supply with very small x-formers that I'm not real familiar with. No schematic. Had to lift about 8 output trasistors before I found the bad one (the last I tested, of course) since one short makes the whole bank look bad. Still won't turn on, so I'm wondering if there is a trick reset, or I have to keep digging.

[Gtr_tech]

THE Analog Mike aka Analogman? Anyway....the SMPS is prolly going into protect due to a bad driver causing a bank of output devices to turn full on and draw a bunch of current. Go back over the driver section and check that all out.

[Analog Mike]

Thanks, I'll re-check the drivers...just "Analog Mike"