Here are some instructions for checking the signal strength on the Comcast DVR [comcastdvrcodes, newcomcastdvr] and how to reset it. I can't remember where I found these instructions, so I apologize to the original author. If you know the source (avsforum? HDTV-SFBay-Users?), please let me know and I'll give proper credit.
WARNING: Don't follow these instructions unless you know what you are doing! You might ruin your DVR, which will probably make Comcast very upset! If you botch things up, it ain't my fault. These codes might not even work on your DVR model!!!
Check the SNR on diagnostic screen 4. It should say good or at least fair. If it says fair or poor it may freeze and pixel occasionally. Check this by:
- Tune to a digital channel.
- Turn the box off (leave tv on) and immediately press the ok/select button.
- Scroll down to #4 and press ok.
- Press the power button twice to turn the box back on.
If the SNR is poor you have a weak signal and a tech would need to fix it. If it is fair the signal may be borderline and only freeze occasionally.
WARNING: Doing this will ERASE all programs from your DVR, and cause your DVR to loose all guide information until it's reloaded (24 hours or so) This process basically resets the hard-drive. You have been warned.
Ok with that said turn your TV and DVR on.
- Press Cable
- Press Power
- Quickly press OK (in the middle of arrow buttons) after your DVR shuts off
- With diagnostics page on screen press: Replay (15 second rewind) One time, DVR (white button on remote) THREE times, LIVE (to the right of DVR) One time
- You will now see "Clr" on your DVR's display
- Press OK
Your DVR will now reset and begin to download… If you see the letters 'DL' this means you are in a VOD area and you won't be able to watch tv for about 20-30 Minutes.
I had a Comcast DVR flake out on me (bad hard drive), and tried a reset. It didn't fix the DVR, and actually seemed to confuse it even more. If you are a Comcast customer, and have trouble with your DVR, I highly recommend calling customer service to exchange the unit. The newer models are general more stable and have quieter hard drives.