HDMI (both Direct TV DVR and XBOX) are not being recognized by the receiver. Working well for 3 + years and just started problem yesterday. Checked HDMI cable and validated audio and video signal by direct connecting to Pioneer Kuro Elite. Performed the reverse handshake HDMI drill and the microprocessor reset to no avail. Denon Tech Support says possible motherboard problem but does anybody have any other suggestions. Excellent receiver until a couple of days ago. CD and Tuner work well. On TV screen Menu also displays. Thanks in advance. I would really hate to upgrade after only 3.5 years to gain HDMI connections again.