Problem: MCE does not change channels properly

I didn’t write this article, Greg Edwards did, but I wanted to post it now because I’m getting emails about set top box channel changing problems and want you all to have a happy set top box experience so knock yourself out!


Title: The Media Center remote control does not change channels properly.


Symptoms:


Even after learning your set-top box remote control, the Media Center remote control does not change channels properly.


Cause:


Media Center may have misjudged the speed of your set-top box’s remote control, and therefore your Media Center remote may be sending signals incorrectly.


Resolution:

  • Using your keyboard, press WINDOWS + R.
  • In the “Run” box that appears, type “regedit,” and click OK.
  • Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Media Center\Service\Video\Tuners
  • Look in subfolders whose names are in curly brackets and contain a bunch of random numbers and letters until you find the UserSettings folder. (There may be multiple folders with this name.)
  • Click on UserSettings, and open the “STBCode” file on the right-hand side of the window. (If this file does not exist, go back to Step 4.
  • Try changing the number contained after the <keyinterval> tag to 100, 175, and 250. Each time, close out of the registry, restart your system, and try your remote to see if it works normally.
    • If you have a Scientific Atlanta 8600 set-top box, change the numbers after the , , and tags to 100, 100, and 400, respectively.
    • If you have a General Instruments DCT 2244 set-top box, change the numbers after the <keyinterval>, <keyduration>, and <channelpause> tags to 1000, 300, and 1200, respectively.


If you want to tweak the numbers further, here is more detailed information:


The value of Key Duration is defined during set-top box setup. The other two registry entries are left blank by setup, and the values for Key Interval and Channel Pause are calculated in the following way:


Key Interval = Key Duration
Channel Pause = 2 * Key Duration

Key Duration Key Interval (Default) Channel Pause (Default)
FAST 100 100 200
MEDIUM 175 175 350
SLOW 250 250 500


If XXX for Key Interval and YYY for Channel Pause are replaced with numeric values, they are used instead of the defaults.


If your box seems to be dropping digits, try a longer Key Duration. If that doesn’t help or doesn’t fully solve the problem, try a longer Key Interval.


If the box is mixing digits from the previous channel change into the current one, try adding to the Channel Pause, and then Key Interval values.

NOTE: all values are in milliseconds, were 1 millisecond is 1/1000 of a second.

Repro Steps:

  • During TV set-up, use IR learning on the remote controls of certain set-top boxes, such as Scientific Atlanta 8600 or General Instruments DCT 2244.
  • While watching television, try to change the channel with your Media Center remote control. It may not change properly.

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