Hello, I am a newbie here. I have a pre-amp only receiver which is giving me some trouble, and Im hoping for some help. I have a Sherwood Newcastle P965 receiver which quits putting out audio after warming up. It doesnt matter if its in stereo or surround mode. After about an hour...no output. I am looking for a schematic, and someone to walk me through some testing. The good news is that I can make it happen routinely to troubleshoot. Help!?!?