"John-Del" wrote
Most HDMI failures are either from corrupted firmware or a bad HDMI
transceiver chip. Follow the fine foil lines from the HDMI jack to an
IC. Get the number off it and check on line for the datasheet.
That's what usually causes the problem. HDMI ports are notorious for
being whacked by lightning hits, and it doesn't take much.

The DVR menu says HDMI ENABLED, but not ACTIVE. The re-activation didn't
help, and my cable provider couldn't (or wouldn't) tell me where they get
their rented DVRs repaired. Since I own the box, I phoned around for
estimates, but none had ever fixed any of these, and so they told me that
the repair cost would likely be higher than buying a new one.

If I knew for sure that a particular chip was defective, I would probably
try replacing it myself, but I think it makes more cost-efficient sense to
just get another one. Appreciate your reply.