Daneurys,
The Pioneer Elite VSX-92TXH has double insulated AC power wiring inside. That is why the manufacture is able to use a 2 wire power cord and plug. The Pioneer's chassis is not designed to be grounded to the safety equipment ground of the wall receptacle.
Grounding the receiver could do more harm than good. It also would not stop the hum.
What audio/video equipment is connected to the receiver through ICs, or video coax cables that use a 3 wire power cord and plug that uses the wall receptacle safety equipment ground?
Also as Swampwalker asked do you have Cable TV connected to the Pioneer Elite receiver? If so for a test disconnect the cable provider's incoming RG6 coax from the cable box receiver and see if that stops the hum.
.
The Pioneer Elite VSX-92TXH has double insulated AC power wiring inside. That is why the manufacture is able to use a 2 wire power cord and plug. The Pioneer's chassis is not designed to be grounded to the safety equipment ground of the wall receptacle.
Grounding the receiver could do more harm than good. It also would not stop the hum.
What audio/video equipment is connected to the receiver through ICs, or video coax cables that use a 3 wire power cord and plug that uses the wall receptacle safety equipment ground?
Also as Swampwalker asked do you have Cable TV connected to the Pioneer Elite receiver? If so for a test disconnect the cable provider's incoming RG6 coax from the cable box receiver and see if that stops the hum.
.