Interesting observation re: toxic channels (TWCNYC)

[alee]

This is TWC NYC (Lower Manhattan). 2 SA cards. Everything working fine for the last year. Been plagued with toxic channels for about 10 days now (seems to have coincided with 9.1, and has not gone away with 9.2).

Symptom: Freeze/spontaneous reboot when tuned into toxic channels. TiVo becomes unresponsive to remote. Disconnecting the cable feed clears things up, allowing me to change the channel to a non-toxic one, after which everything is fine.

Did some digging this evening and this is what I've found:

Under Settings -> Channels -> Signal Strength - Cable

I tuned to a few HD channels, and let it sit there for 2-3 minutes to let the signal settle in, and to pick up peak readings. I've noticed that on all the "toxic" HD channels, I never get a peak reading, even though I get a signal strength that is well within acceptable tolerances.

So for non-toxic channels... you can clearly see I have peak readings (which typically appear in about 5 sec):

http://www.leesoft.com/temp/tivo/nontoxic708.jpg

http://www.leesoft.com/temp/tivo/nontoxic718.jpg

For the toxic channels, you can see that my peak is always zero, no matter how long I wait. For whatever reason, WNETDT (713) shows absolutely no signal, although the picture is crystal clear (WNETDT has always been crisp and clear):

http://www.leesoft.com/temp/tivo/toxic705.jpg

http://www.leesoft.com/temp/tivo/toxic713.jpg

I'm not sure what this means in the scheme of things; however, my TiVo S3 is definitely crippled on about a half dozen HD channels right now. Not sure if something changed with 9.1/9.2, or if TWCNYC made a change.

Interested to hear everyone's thoughts...

[rodalpho]

I have a S3 with SA cablecards under TWCNYC lower manhattan too. I have the exact same lineup you do, and no issues with toxic channels or rebooting. I do get pixellization and audio dropouts, but no crashes. Try replacing your cablecards, maybe?

[alee]

I have a S3 with SA cablecards under TWCNYC lower manhattan too. I have the exact same lineup you do, and no issues with toxic channels or rebooting. I do get pixellization and audio dropouts, but no crashes. Try replacing your cablecards, maybe?
Interesting. I've been dreading talking to TWCNYC since things otherwise seem to be working... what sort of signal strength are you getting on 705, 708, 713 and 718?

[rodalpho]

705: 100 signal, 36dB SNR, 0 uncorrected, 0 corrected
708: 100 signal, 36dB SNR, 0 uncorrected, 0 corrected
713: 95-100 signal, 35-36dB SNR, 0 uncorrected, 0 corrected
718: 100 signal, 36-37dB SNR, 0 uncorrected, 0 corrected

Note that the uncorrected/corrected numbers come after <1 minute on the channel; normally I do get some of both.

If you have toxic channels rebooting your machine, not talking to the cable company because "otherwise things are working" doesn't make a great deal of sense. Minor pixellation, OK, fine. Rebooting? Not so much.

[alee]

If you have toxic channels rebooting your machine, not talking to the cable company because "otherwise things are working" doesn't make a great deal of sense. Minor pixellation, OK, fine. Rebooting? Not so much.
True... just systematically eliminating things before I call them. We all know TWC's stance on cable cards... just want to make sure I tried everything else before listening to them lecture me how cable cards are evil.