I have a Zenith DVD/Stereo Combo home theatre system. I bought it
about 3 years ago. It worked very well until recently. It made a pop
noise while operating and the unit powered off. Now if you try and
power up the reciever, it will emit a high pitch frequency for about
half second and completely shut down. If you try and power it up
again, nothing happens but if you unplug the unit, wait 2-3 minutes
and plug it back in, the unit will enter standby mode and the red
indicator light will be on. Then if you hit the power button to turn
the unit into active mode it will emit the high freq. noise again and
shut off. Any advice you can give me on what the problem could be and
how to fix it would be greatly appreciated.

Thanks,
Craig