Went to listen to some stuff later last night and thee AVR comes on then shuts off (display and sound)though the power button is still illuminated. It seems to only happen in surround mode as if I kick it over to stereo it will stay on.

Haven't checked anything out, but going to check all speaker connections, especially center channel; but nothing has been moved recently.

Other things I should check for?

Mark, yes the first thing is to check the speaker wiring(re do it even if it looks good)for a possible loose wire in the center or surrounds causing a short.

If the external wiring connections are okay, it's possible that one of the center or surround speakers has developed an internal short. Disconnect one of those speakers at a time to see if operation is normal when it's not connected.

Well the center channel I noticed had been pushed back about an inch. Put it back in its location and redressed the wiring to it and all seems OK again.