HT-S6300 (HT-R680) Receiver HDMI Problems

I purchased an HT-S6300 7.1ch Home Theater System (HT-R680 receiver) on 11/21/2010 from HHGREGG.

I no longer have a signal from my receiver to my TV and have been through every possible setting and test. Experiencing no audio/video signals via HDMI cabling even with new HDMI cables. TV works fine with HDMI running directly from DVR/cable box. I do have audio through the speaker system, however.

Through some internet research on the problem, there appears to be a high frequency of HDMI board failures.

I'm assuming the unit is still under the 2 year warranty?

What is/are my best options/steps/process for returning the unit for repair, replacement or DIY fix?

Thanks