Originally Posted by
TedJM 
Note: I don't believe that this is related to PSIP (Program and System Information Protocol) data
downloads from the individual broadcast channels.
This has been successful for me and a few other people that asked me for suggestions to
help them recover their TV Guide updating and/or previously deleted channels.
I call this a 'System Manual Reset':
>> Rescan for channels, Time, etc. by going to the following:
Press the 'Menu' button. Select - Setup (3), System Setup (2), Installation (1), Setup Wizard (1),
press the 'Select' button. Note that even with Cancel highlighted in the Setup Wizard, pressing
'Select' will start the process. If you want to Cancel, you must press the 'Cancel' button.
This is much easier than doing a Factory Reset, because all of your Menu preferences you previously
made will be retained. Although YOU WILL HAVE TO re-enter your Program Recording Schedule (if you currently have one) in the Program Guide, but this is easy to do, just make some notes about it before performing the reset.
Please let us know if this works for you. I'm sure others will be interested in your results.