Hi Guys I've been asked to take a look at a friends 2000 avt 275. There's absolutely no sound AT ALL coming from it, not even through the headphone socket. I changed the 12AX7, and I've jumped the effects loop, but still nothing. Also, there's no LEDs on the front panel switches. He didn't leave the footswith with me, but surely you can manually switch without the footswitch???? Any help much appreciated Ta!