Several Clear QAM Digital Channels suddenly won't record or display

[mian]

... Except in the digital channel mapping utility. If I try to play live TV for NBC, ABC, CBS, Fox, The CW or pBS digital, then either nothing displays or a no signal prompt comes up requesting that I check the connections and signal strength--scheduled recordings come up as 0kb files. 4 or so other QAM digital channels still come in as clear as always, though I think all those working digital channels transmit SD digital, as opposed to all the listed ones that transmit HD digital. It has been this way for 4-5 days.

Since the last time this worked (earlier this week) I have not:
* made any significant software changes (I installed Google earth yesterday, but the problem preceded that by several days. I installed Hulu desktop recently, though I don't recall exactly when--and that's it.)
* made any changes to GBPVR settings or installed a new version
* added or taken anything away from my home's cable connections, everything that was plugged into a cable port last week is still plugged in and nothing new has been plugged in and no add'l splits have been added anywhere.

Since it stopped working, I have:
* Confirmed that all the non-working channels are still selected in at least one digital tuner
* Confirmed that the mappings are still correct in the digital channel mapping utility (GBPVR Config -> Capture Sources -> Edit (for a digital tuner) -> map digital channels to EPG Channels -> Scan, preview).
* Listened carefully to the audio during the mapping previews to hear any distortion (none so far), and watched for pixelization or skips, which would be hard to spot given how scrunched the preview window is, but I haven't noticed anything unusual
* Checked my cables to make sure they are tight and properly attached.
* Confirmed that all three tuners work perfectly fine on analog channels
* restarted both the recording service and my PC several times with no change in result
* temporarily removed the splitter that splits the wall cable to my Convertx and 2250 to see if going from the wall straight to the 2250 would all digital channels to come in: it doesn't

Admittedly, during the scan, it shows a Strength of -20 and Quality of 100 (the strength certainly sounds low), but the preview sounds and looks clear and strong. Also admittedly, my neighborhood is seeing some new home construction occur in nearby vacant lots as well as some recently built homes probably just getting cable--so there might be some reason to suspect signal strength drop from something done outside my house.

What I don't understand is why the mapping utility will play the channels but PVRx2 and the recording service won't. I can't call my cable company until tomorrow anyway, so I thought I'd fish for suggestions.

My system specs in my sig is up to date, same tuners, same drivers, same GBPVR install. My next steps if you all have no ideas are to 1) upgrade my 2250 to the latest 27223 driver at hauppauge 2) remove all digital mappings, save, rescan and remap to the epg 3) reinstall GBPVR or upgrade it.

Thanks.

[Snooze]

If your 2250 is anything like my 1600, it is really fussy with signal strength changes.

1.Maybe you could try completely disconnecting the power to your PC for about 30 minutes and see if that resets the tuner card.

2. I played with splitters to actually add signal loss (both 3.5db and 7db). If I run it straight in it seems the signal is too strong. Maybe your signal strength has changed due to the new construction +/-?

[whurlston]

Can you post a set of logs showing where you view the channels in Config, then attempt to record one of the problem channels, then attempt to view live TV on a problem channel.

[mian]

Thank you both very much. I'll try to post logs using that methodology this evening when I get back home.

Do you want a/some specific log file excerpts showing the activities, or all log files zipped up that have entries during the testing period?

[crossnet]

I've had the same problem and believe it was due to the cable company changing something in the signal assignment. Same symptoms, able to see the preview in the scan, but not on screen. I was able to fix this only by deleting the DBA cache file for the specific tuner(s) and rescanning. (You should make a backup first).

emr

[mian]

I've had the same problem and believe it was due to the cable company changing something in the signal assignment. Same symptoms, able to see the preview in the scan, but not on screen. I was able to fix this only by deleting the DBA cache file for the specific tuner(s) and rescanning. (You should make a backup first).

emr

Bingo! Crossnet, you are the bomb. You saved me a ton of time that I don't actually have to spare this week, not to mention I probably would have created some new problems working through the step by step on my own. Thanks