CRAZY video issue.. almost HAS to be receiver?

[Uniquely]

I've been having a problem with my 360 for several months now. It has been getting progressively worse and is now unplayable. The video output will black out momentarily, yellow lines will appear from top to bottom, and sometimes the screen will go completely snowy. This problem used to just occur for the first few minutes the system was on and then go completely away, but it is now constant.

The steps I have taken to try to track down the issue and fix it, now have me completely baffled. My first thought was that it was the video card on the XBox, so I got a whole new 360. It has the same issue. My next thought was that it was either the HDMI cable or the HDMI input on my Onkyo 606 receiver, so I pulled the HDMI cable from my PC, which was working fine, and plugged it into the 360; still the same issue. I had an epiphany about a strange video problem I had a couple of years ago where the hd dvd drive connected to my 360 would allow video to play but not in-game video, so I unplugged the newer hd dvd drive... still the same issue. My final thought was that it had to be the 360 power brick since that was the only thing I had not changed (it's a pain to get to behind my 12ft ent unit.) I went through the massive effort to change the brick and still have the same issue.

The set up is as follows

360, blu-ray, sat receiver and PC all plugged into an Onkyo 606 receiver via HDMI, and then a single HDMI cable out to my Samsung DLP. The blu-ray player, sat receiver and PC all play fine. I can't get behind my receiver to swap inputs without dismantling my whole GIANT ent unit (see pics in set up link.) However, unplugging the PC HDMI and putting it into the 360 is essentially the same as trying a new input.

I'm to the point where it HAS to be the receiver, but I am leary of buying a new receiver since the input currently giving me problems with the 360 seems to work fine with the PC. Does anyone have ANY other ideas?