Is a 90 signal strength too weak?

Discussion in 'TiVo Help Center' started by driverseven, Aug 22, 2011.

  1. driverseven

    driverseven Tivo Bolt

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    Oct 11, 2007
    Westchester, NY
    I am trying to debug a Tivo Series 3 HD that is suddenly missing channels.

    It started a few weeks ago after years of working fine. A Tivo reset will fix it for a day or two.

    In most cases, the channels will eventually come in. Sometimes it takes 20 seconds and sometimes up to 10 minutes -- we have tried all the tricks (changing channels, switching tuners). The Tivo signal strength meter shows 89 to 92 on most channels.

    We have Cablevision Optimum IO and the other 3 TVs in the house (one with a Tivo Series 3 HD) are not experiencing problems.

    I have searched around here and read all of Tivo's online troubleshooting. With a signal strength of 90, I don't think my cable company is the answer.

    I am planning on trying Tivo's call support line next but wondered if anyone else thinks it's the cable strength.
     
  2. dlfl

    dlfl Cranky old novice

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    Jul 6, 2006
    Dayton OH
    90 should be plenty. What is the SNR? What are RS Error counts doing?
     
  3. lpwcomp

    lpwcomp Well-Known Member

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    John's...
    Could be a CableCARD problem.
     
  4. driverseven

    driverseven Tivo Bolt

    48
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    Oct 11, 2007
    Westchester, NY
    I'm not sure what this means, but here's the data...

    Tuner 0
    SNR: 35 dB
    RS Uncorrected: 35
    RS Corrected: 1390

    Tuner 1
    SNR: 35 dB
    RS Uncorrected: 255
    RS Corrected: 1551

    I'm curious to hear what it means?
     
  5. dlfl

    dlfl Cranky old novice

    8,883
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    Dayton OH
    The SNR values are good.

    Ideally the RS error counts should be zero. The values you see may or may not be bad depending on what they do over time. If they are increasing rapidly that would indicate a problem. If those counts were for an hour or more of being tuned to those channels, they would be of little concern. The same diagnostic pages tell how many seconds the channels have been tuned. Monitor the counts for ten minutes or more and see how fast they are increasing. An RS Uncorrected error count of zero means you have detected the signal exactly as it was originated on the cable system. RS Corrected errors mean there were errors but they were corrected by the error correction system.

    It's puzzling and very unusual if you are getting signal errors with 90 strength and 35 dB SNR. I suppose it could result from problems either with the Cable co equipment or in the TiVo. Only on very, very rare occasions do I see any error counts other than zero on my cable channels and these are always isolated incidents, i.e., the counts jump once but don't increase even over hours sitting on the channel. The counts you observed will correspond to a video glitch of a second or so if you happen to be viewing when the errors occur.
     
  6. driverseven

    driverseven Tivo Bolt

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    0
    Oct 11, 2007
    Westchester, NY
    I've reset the Tivo and the RS errors are down to zero after 8 hours.

    I chatted with Tivo support and they said it's either the cable card or the Tivo tuner.

    I guess I'll have to get Cablevision out here to get new cards.
     
  7. lpwcomp

    lpwcomp Well-Known Member

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    John's...
    If Cablevision requires that CableCARDs be paired to the TiVo (probable), verify that they are before you request a technician. You shouldn't require a technician for anything that can be done inside your home.
     
  8. driverseven

    driverseven Tivo Bolt

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    Oct 11, 2007
    Westchester, NY
    lpwcomp: The cablecards have been working for 3 years now before this problem developed.

    Are you saying that there is a way for me to get new cablecards on my own? I would gladly go pick them up and go through the process myself if it were possible.

    dlfl: 18 hours after a Tivo reset, the RF levels are risely slowly...

    Tuner 0
    SNR: 35 dB
    RS Uncorrected: 2077
    RS Corrected: 2515

    Tuner 1
    SNR: 35 dB
    RS Uncorrected: 106
    RS Corrected: 124

    At this point, I'm trying to decide whether it is worth going through the trouble of getting cablevision to replace the cable cards or to just tell Tivo that the tuner is shot. They said they will replace it for $149.
     
  9. lpwcomp

    lpwcomp Well-Known Member

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    John's...
    It's possible the CableCARDs have gone bad or at least somehow lost pairing.

    Look to see what your TiVo has on the "Conditional Access" screen.

    Probably. As of August 8, if your cable company allows self-install of anything, they are required to offer self-install of CableCARDs.

    This a TiVo model TCD648250, correct?
     
  10. Pokemon_Dad

    Pokemon_Dad Ruler of Unown UI

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    Silicon Valley
    It is quite possible that the problem is entirely outside your house, on a pole somewhere. This part of your service is probably the responsibility of a different division in Cablevision, and they will probably insist that CSRs and in-home techs evaluate all other possibilities before they agree to look at variations and hiccups in the signal they are delivering. It's especially time-consuming for them to diagnose when the problem changes over long periods of time, as you are reporting.

    In my case, here in Comcast Land, after over a year of problems with the Internet and a small group of TV channels, only in the winters and only in the early morning (when the temperature dropped below 40 degrees; I'm in California), after seven tech visits in which every jack and piece of equipment in our house was evaluated, I escalated the problem to Corporate and was able to get the "Network" division to take this seriously. Previously they blamed the techs or my equipment every time, without looking carefully.

    Water had gotten into a tap up on a nearby pole. That's all it was. In your case, maybe the same thing or maybe it's a bad transformer up the line. Transformers not getting enough current can slowly rise in output over time, just as you are describing. But you may have to get very aggressive with Cablevision before they will even look at this possibility. I hope it's not a network problem you have there, but thought this information might be useful to you.
     
  11. lpwcomp

    lpwcomp Well-Known Member

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    John's...
    I'm going to throw something in here even though I have no experience with it and hopefully never will, but could SDV be an issue?
     
  12. driverseven

    driverseven Tivo Bolt

    48
    0
    Oct 11, 2007
    Westchester, NY
    I can't find a "conditional access" screen.

    The model number is TCD 652180 -- a Tivo HD. I was wrong to call it a Series HD earlier. (It is years since I bought this)

    I have another Tivo HD in the house that is not having this issue so I don't think it's outside the house.

    I don't have an SDV Adapter.
     
  13. lpwcomp

    lpwcomp Well-Known Member

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    John's...
    Since it is a THD, I would at least return the two s-cards and switch to a single m-card. On both THDs, assuming the other one also has two cards in it.
     
  14. Pokemon_Dad

    Pokemon_Dad Ruler of Unown UI

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    Conditional access is one of the CableCard setup screens. Your HD has one, keep looking. If it says "Con = yes" towards the end of the first section of gobbledygook text, then a card is properly paired. It may not be working right, but it is paired with the system.

    I'm still thinking fluctuating RF signal levels are due to something entirely outside your house.
     

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