What's the source of this channel loss problem?

Discussion in 'TiVo Help Center' started by tivogurl, Jan 27, 2012.

  1. tivogurl

    tivogurl New Member

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    Dec 15, 2004
    I have a TiVo HD hooked up to a Cox tuning adapter.

    I have a Season Pass for the New Outer Limits on Chiller. The TiVo is usually on standby when I'm not home.

    1) If I have no tuners tuned to Chiller, about half the time the channel change will end up with no signal, causing no recording to be made. If I were there, a channel up/down two-step usually causes Chiller to give a signal.

    2) If I have a tuner tuned to Chiller, about 1/4 of the time either the signal will be lost before the recording starts, causing no recording to be made, or it will be lost in the middle, causing the recording to be truncated.

    What's causing this signal loss? Is the TA just dropping the channel without asking the TiVo if it's still interested? Is the TiVo not responding to the TA? Is there any way to stop this from happening?
     
  2. dlfl

    dlfl Cranky old novice

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    Jul 6, 2006
    Dayton OH
    This SDV-tuning failure is an old and continuing problem and you can find numerous posts about it if you search. Neither TiVo nor the Cable Cos will admit responsibility for it and so they do nothing about it. Some of us believe TiVo could fix it with a software mod that would, in effect, automatically do the re-tune similar to what you do when you tune up/down manually. Having a channel already tuned makes no difference because when TiVo starts a recording it re-tunes the channel, even if a tuner is already sitting on the channel to be recorded, and that tuning op may fail.

    It would take some engineering and test effort to diagnose what the actual problem is and apparently no one is willing to provide that. Last I heard the problem exists also on the Premiere models although I haven't heard about the Elite model. I assume only a small fraction of TiVo users experience major problems with this or there would more clamor to get it fixed. I've always had it but, for completely unknown reasons, it has happened a lot less frequently in the last month or two.
     
  3. tivogurl

    tivogurl New Member

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    Dec 15, 2004
    If the TiVo didn't do that, then the random channel loss bug would become a problem. I've noticed that if my TA has dropped a channel, you cannot retune the channel to get it back. You must move to a different channel and then go back to the dropped channel.

    Interestingly, channel up/down is much more reliable at this than selecting by channel number the alternate channel followed by selecting by channel number the original. This is so even if the alternate channel is the same one you'd get by selecting channel up. This is odd, because I thought TiVo implements "channel up" by selecting a specific channel number.
     
  4. tivogurl

    tivogurl New Member

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    Dec 15, 2004
    Is this problem one that can be solved by changing TAs?
     
  5. dlfl

    dlfl Cranky old novice

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    Jul 6, 2006
    Dayton OH
    The SDV tuning failure problem happens with good TA's. But a bad TA couild also be causing some or all of your problems. If you complain to your cable co they will most likely give you a new TA. The signal levels the TA uses to communicate with the cable plant should also be checked. For a Cisco TA at least these are the FDC and RDC found in the first page of TA diagnostics, the values that have units of dBmV. The FDC should be in the -7 to +7 range. The RDC should be in the 35 to 55 range. Values outside those ranges could cause your problems and this will require adjustments by the cable co. or possibly some corrections in the wiring and splitters in your home or facility.
     

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