Posted for everyone's benefit as TV stations are continuously updating their PSIP streams, or channel mappings with additional information, and in many cases, you might suddenly not be able to receive their signal. When you review the signal strength its 0 or red. Here's the full instructions on how to resolve this issue...
Before you begin, you need to configure Vista/XP such that you can see the hidden files you will need to edit, so CLOSE MEDIA CENTER and then:
1. Open My Computer – Click on Start and then My Computer
2. Press the ALT key to have menus show in Vista
3. Click the Tools Menu
4. Select Folder Options
5. Click on the View tab
6. Select “Show Hidden Files and Folders” and uncheck “Hide protected operation system files”
7. Click apply
8. Now click the “apply to folders” button to make the settings hold for all folders.
Find the file you need to edit in the c:\ProgramData\Microsoft\eHome\EPG\prefs directory:
1. Open My Computer – Click on Start and then My Computer
2. Double-click on the C drive
3. Double-click on ProgramData directory
4. Double-click on Microsoft directory
5. Double-click on eHome directory
6. Double-click on EPG directory
7. Double-click on prefs directory
Edit the atscchannels.xml file to remove the channel from Media Center: In this example, the TV station is KCRG which currently broadcasts on 52 but has a major channel of 9 and the default 1 minor channel. Do a quick google to find the physical channels for the stations in your area....
1. Right-click the file atscchannels.xml and select Edit from the popup menu
2. Find the line that reads: <channel callsign=”KCRG” version=”0” physical=”52” major=”9” />
3. Delete the line
4. Save the file (File, Save) and Close (click the X in the upper right-hand window)
Start Media Center and add the channel back:
1. Start Media Center
2. Select settings from main menu
3. Select TV
4. Select Guide
5. Select Add Missing Channels (you deleted the channel by editing the xml file above)
6. Select Add DTV Channel
7. Enter the Major number of 9 (substitute your station here) and the minor number of 1 should be automatically entered.
8. Select Next
9. Enter assigned frequency of 52 (substitute your frequency here - google for it)
10. Select Next
11. Select Finish
12. Select Done
13. Select Back on your Remote
14. Select Digital TV Antenna Signal Strength (if you have scheduled recordings, answer YES)
15. Select Next
16. Watch the channel checks as they scroll by and you should now have a signal from KCRG
This process has worked multiple times as one of our stations in the area "tweaks" the channel mappigs quite a bit.