I build a home theater room utilizing a isolated cabinet for all of the home theater equipment. All of the equipment is on its on 20A circuit. The equipment in the cabinet includes;
1x Onkyo TX-NR515 Reciever
1x AT&T U-Verse Internet and Cable
3x Monoprice 1x2 HDMI Powered splitters
1x Monoprice 4x4 HDMI to Cat5e/Cat 6 Matrix with IR
The PS3, HTPC, and U-Verse cable are all connected to the HMDI splitters so that the signal can be split and and sent either to the Matrix or to the Onkyo receiver. The matrix is currently running 2 TVs in other areas of the house via HDMI over Ethernet capabilities over Cat6. The Onkyo receiver is running one 60" LG plasma TV in the home theater room over another separate HDMI to Ethernet with IR extender. The LG TV is on a completely separate 15Amp circuit that only shares a ground and neutral back at the breaker.
My issue is I have a grounding issue between the ground and neutral when the Onkyo receiver and the LG TV are connected via HDMI. When connected I get anywhere from 15 to 120Ohms at my outlet furthest from the breaker. As you would expect this is a problem and causes voltage to build up between the two and when I touch anything metal that is a part of the circuit (TV, screw on an outlet, etc) there is a small arc. Flipping a light switch that is on that same circuit as the TV can cause the HDMI signal to flicker or black out for a few seconds.
I have tried and checked various things.
- There isn't a grounding issue on the 20Amp circuit when this problem is occurring on the 15Amp circuit.
- When the HDMI is unhooked from anywhere between the Onkyo Receiver and the TV the ground to neutral resistance drops to less than 1ohm.
- I have replaced the HDMI to ethernet extender.
- I have checked all of the grounds in all of the outlets and switches on the 15amp circuit.
- When the volume is turned up on the Onkyo reciever the resistance from neutral to ground is higher.
I don't really know what else to do. I would like to find a lower cost option (I don't want to replace the TV and/or receiver).