How do I make an HP HDTV auto-detect the local digital channels when using rooftop antenna?

Question

At first, while surfing through the local channels I would only see the analog channels, but one day I noticed it was set on Cable, so I changed it to Antenna and the auto search then found digital channels. I don't think I did anything else, but now I can only access analog channels again and it says Antenna in the channel setup.

Answer 1

Digital off-the air reception is very sensitive to the direction of your antenna. If you move it, even by a few degrees you can lose reception.
Check www.antennaweb.org for the best direction for your antenna. Then do a rescan.