Denon AVR-4310-CI Home Theater Receiver AS-IS

This receiver really has me stumped. During testing, I am only getting sound from certain settings and not others. With an analog source connected to CD input, I was getting sound from all the DSP modes like jazz, rock, 5 channel stereo etc. But from direct / stereo mode - no sound. Going into the 6 channel direct inputs on the back, I was able to get sound from front Left / Right channels but not the others. So if nothing else, this unit can be used for a nice 2 channel amplifier. Beyond that, it's offered for parts / repair only.

Cosmetic condition is good, but the hinge on the door on the front is broken. Some other exterior wear visible. See photos for details.