My Yamaha RX-V440RDS does not send out any signals to the speakers when in Stereo mode. It does however seem to work properly when in the other modes such as DTS. When I try switching from a working mode and back to Stereo I can hear it snap like it does when you turn it of and it does not give any sound, but the display is still on. Turning back to another mode and I will hear it snap on and there is sound from the speakers. I do have the manual but cannot find anything similar. Any clues?