Signal Quality from Diagnostics Page

Discussion in 'TiVo Series3 HDTV DVRs' started by BitMonkey, Aug 17, 2007.

  1. BitMonkey

    BitMonkey New Member

    Aug 16, 2007


    I'm hoping that others out there can share with me what their signal levels are from the diagnostic page so that I can figure out whether or not I have a defective unit, and possibly shedding light on whether other people who report problems specifically with cablecard 2 are having signal problems.

    The symptoms I have is that if I tune both tuners to digital channels and use the diagnostics page to view the signal level, it will show tuner 0 with signal level 93 and SNR 35. Tuner 1 will show signal level of 43 and SNR of 28, that is if I get it tuned to one of the digital channels that it can tune. The large drop in signal and SNR indicate a possible internal hardware problem with tuner 1.

    Another symptom of this problem, if I pick one of the digital channels that only tuner 0 can tune than when I do the signal test on that channel, it will read signal level 93 and below it will show 'Digital Signal Aquired (no signal tuner 1)'.

    To verify my cablecards are working properly, I took turns binding each cablecard to tuner0 and checked the channels. You can pick which tuner is bound to which cablecard by taking advantage of the fact that when a tuner moves from an analog to a digital channel it will grab the CC1 if no cablecards are being used.

    For example, to ensure that tuner 0 get CC1, tune both tuners to an analog station and then when on tuner 0 dial in a digital channel. Check the diagnostics screen and you should see the association of CC1 with tuner 0. To get tuner 0 to use CC2, first tune both tuners to analog and then switch to tuner 1 and dial in a digital channel. This will associate CC1 (since both are free) to tuner 1. You can check diagnostics again to verify. Next, move to tuner 0 and dial in a digital channel, it will grab CC2 since it is the only one available.

    Using this method, I was able to verify that tuner 0 with cablecard 1 and cablecard 2 will tune all digital channels that I've ordered. Running tests with tuner 1 using cablecard 1 and cablecard 2 give identical results - that only some channels can be tuned and heavy macroblocking persists on the channels that it can tune. The channels that it can tune always have low signal level and SNR similar to the example above.

    So, I feel fairly confident that I've isolated the problem to tuner 1 and that both cablecards are operating properly. All of this testing here was done after the software upgrade to 8.1.7b2. 8.1.7b1 gave the same results.

    The trick now will be to explain this to TiVo and convince them to send me another hopefully good box.

    It would help if someone could provide feedback on the signal levels of both tuners, and ideally if TiVo HD has two SA cablecards, running the same software that mine do. I wrote up full details of the hardware in the thread 'New TiVo HD Software Update'. Sorry I can't link, I'm new here and am restricted from doing so until I hit 5 posts.


    - BitMonkey
  2. BitMonkey

    BitMonkey New Member

    Aug 16, 2007
    OK - I have an update for you all. Good news and bad news.

    The good news is that I was able to get TiVo to send me a new unit, and the new unit is working properly. I have two SA cards - so now I'm in the same boat as most people here - frequent pixellation issues.

    The bad news is that I can almost definitely say that there was a hardware problem with my original TiVo HD. Both TiVos running the same version of code, same cable signal input, same cablecards. The original TiVo I received just had a busted tuner, tuner 1.

    I have seen a couple people post with similar symptoms that I had - no troubleshooting from TiVo or the cable company is going to fix it. My advice to you is troubleshoot it to see if it is the same issue as mine and then call TiVo with 'I have a bad tuner 1, send an RMA'.

    The easiest way to verify is probably to tune analog channels on both tuners - if one tuner has a noticeably worse signal - grainy picture - than you may have this problem. You can also take turns with the tuners tuning the same digital channel while checking the diagnostics page. If the same channel shows up with significantly lower signal lever and SNR than the other tuner - than you most likely have this problem. Both tuners show the same signal and SNR for the same channel on my new unit.

    Looks like TiVo may have had a bad hardware run of the new model, let's hope it was a small amount.

    Hey TiVo, if you are reading this - write a little program that detects the signal level of the tuners for your next software release and flag the boxes that have this problem. Then you can actively recall these defective boxes.

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