Tonight I went back to work for the first time since my surgery.
Two different friends filled in for me while I was off for two weeks and both used my p.a. system.
I went in 30 minutes early tonight so I could set up and have time to fix anything they might have moved, turned, unplugged, broken, etc.
Well I hooked my Yamaha AG06 mixer back up, plugged everything in and turned it on.  Everything was fine except the mixer.  It wouldn't come on.  It is powered by USB cable.  I changed the cable.  Nope.  I plugged the cable in a different power supply.  Nothing.
I run my keyboard into a stereo channel on the mixer, and the laptop into another, so I can play music on break.  I also have a guest mic hooked up to it.  And I usually hook up my digital recorder and record myself from the mixer.
 Fortunately none of this is essential. It was time to start so I bypassed the mixer and just ran the keyboard left and right out into the powered speakers, then ran the laptop into the external inputs on the PA4X.  I didn't have any guest singers.
When I finished I brought the mixer home.  I figured I would either see what the problem was or take a different mixer tomorrow night.
I pulled up the owner's manual on the PC and found it had a Power button.  I had never turned it off, and had forgotten it was there.
 It is small and recessed.  Evidently one of my fill-in friends turned it off. All I had to do was push the power button.  
It is usually the simple things isn't it?  
