I just purchased a Denon AVR-987 Receiver to use with my 2 year old Mitsubishi WD-62725 DLP TV. I was excited to be able to upconvert my component video DVD & DVR (and even composite VCR) and use only a single cable to the TV. Much to my chagrin, I cannot get the HDMI connection to work - it shows snow and flashes a brief glimpse of video every few seconds. This is even when I am just doing the system setup.
I recently bought a PS3 and had it hooked up directly to the Mitsu over HDMI and it worked like a charm.
Nope, setup does not work, it does the flash/snow thing also. And PS3 does not work when passed through.
It seems it has to be one of two things
1) Denon site says you need a certified cable and snow or flash can result from a "non-certified" cable. The cables I am using are from my HD DirectTivo (which also had HDMI issues).
2) Mitsubishi is old and not standards compliant? Maybe HDCP issue? Denon says it requires HDCP but so did PS3 and it worked fine.
I will try a "certified" cable but barring that will have to do component video and digital audio (which I suppose is indistinguishable - at least until I upgrade to 1080p on the TV.)
You are wise to try upgrading your HDMI cable. Also keep it as short as you can.
I'm not familiar with your receiver, but many receivers with HDMI output can put up a setup menu or some such on that output independent of ANY source video. If yours works that way then that's your best tool for testing the connection to your TV.
Also, try setting the video output resolution to 480p between the receiver and your TV. This resolution puts the least demands on the HDMI circuit at both ends. If you can get video to the TV that way, but not at higher resolutions, then that too will help locate what's going wrong.
You should also consider posting this question over on the Amps/Receivers/Processors forum here where other Denon owners might be able to help you check whether you have made all the necessary settings in the Denon to enable its HDMI output.
Finally, consider taking the Denon back to the store where you bought it and having them hook it up to HDMI on a TV in the store just to verify that its HDMI output is working at all.