Snowy is unusual. All I had with a dead HDMI output was a dark screen on my TV and no sound when I selected the HDMI input. Others have reported loss of one color or "noise" patterns, etc. In my case it was definitely the 622 that was bad, and I may have caused it inadvertently. One proven cause of the "no HDMI output" problem is broken HDMI socket connections on the receiver's PCB and that can easily be caused by wiggling the plug the wrong way or putting too much pressure on it in any direction. I suppose that could happen with the TV as well. It's possible that while you were moving wires around in the back you did one of those things without realizing it. Now the question is did it happen in the TV or in the 622? I'd bet the 622 since this is so common. Do you have another HDMI source to test the TV's input?
Try all the usual stuff - soft and hard reboots, *gently* wiggling the HDMI plugs, a different HDMI cable, a different source, etc. Failing all of that - time to call E* tech support...