1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Tivo HD Pixelation Troubleshooting

Discussion in 'TiVo Series3 HDTV DVRs' started by Chimpware, Aug 3, 2007.

  1. richsadams

    richsadams Active Member

    8,893
    2
    Jan 4, 2003
    Glad to hear things worked out. FWIW if you start seeing issues again I'd consider replacing the hard drive. I'm not sure which KS resolved the problem, but it was probably KS57 or KS58, both of which correct data corruption and if found, isolate bad sectors on the hard drive. It may have been a one-time thing (power failure, surge, signal, etc.) however if things start going south again it may be time for a new drive.

    Enjoy your "new" TiVo!
     
  2. Jun 1, 2011 #1502 of 1597
    chris98891

    chris98891 New Member

    6
    0
    Jun 1, 2011
    Hey everybody, I think I've had enough.

    I have a Tivo HD with a western digital expander and 2 motorola cable cards as well as a motorola SDV tuning adapter, all of this with Charter Cable.

    I am having SEVERE pixelation and tiling on all of my local HD channels, as well as Comedy Central and TBS HD. The locals are unwatchable for most of the day, but are ok in the evening usually (but not tonight for some reason).

    Charter has already been out once. They tested inside the house (all signals were great), outside of the house (still great) and at the main line (still great) and were perplexed. I have a supervisor coming out tomorrow to check it out.

    What should i be looking for? Everything else runs fine, so I'm having a tough time being convinced its the hard drive. Should I try attenuation? Also, if I remember right, there may be a signal booster installed way back in the day in the crawlspace, should I remove that?

    Thanks for any other help you can give!
     
  3. Jun 1, 2011 #1503 of 1597
    dwit

    dwit Active Member

    1,660
    0
    May 4, 2004
    Atlanta, GA
    Are you also set up for ota(over the air)? Do you get the same issues with ota HD?
     
  4. Jun 1, 2011 #1504 of 1597
    chris98891

    chris98891 New Member

    6
    0
    Jun 1, 2011
    I'm not too sure how to check. The cable guy last time showed me that he could change around a couple wires and I'd lose most of my HDs and my locals would come in perfect, so I'd imagine the OTA HD works fine?

    EDIT: There is a three way splitter between the wall, tuning adapter, and tivo. if i unscrew the tuning adapter from it, my picture improves significantly on some channels

    Note: NBC<CBS<ABC as far as picture quality

    Double EDIT:
    Some more information, my RS Uncorrected and corrected: 0
    SNR: 31dB, signal strength: 56

    on a local channel that comes in decently:
    RS uncorrected: low, 0-200
    RS Corrected: high, easily passing 200,000
    SNR: 27dB, signal strength 42
     
  5. Jun 1, 2011 #1505 of 1597
    dwit

    dwit Active Member

    1,660
    0
    May 4, 2004
    Atlanta, GA
    OTA essentially means do you have an antenna(indoor or outdoor) connected to the Tivo. On the back of the Tivo, the cable(from the cable company) is attatched to a aterminal, and right next to that is another "Antenna" terminal.

    Assuming you are not set up for over the air. You would know it because there usually are a lot of different ota channels that you would have come across while flipping thru channels. This is all set up in the initial guided set up of the Tivo.

    I was just wondering. I am having similar issues and I was pretty sure it was the cable, until I realized the same thing was happening with my ota channels, which of course, are not involved with the cable signals in any way.

    That is just my case though. Yours could very well be the cable, but of course, a bad hard drive is a possibility.

    Looks like you very well could have signal strength issues, after looking at the additional info.

    Good luck.
     
  6. Jun 2, 2011 #1506 of 1597
    SCSIRAID

    SCSIRAID Active Member

    2,321
    0
    Feb 2, 2003
    Vero Beach, FL
    Both of your SNR values are low. I would expect >33 for best results. I would look towards signal strength/quality as the cause. That 3 way splitter concerns me. You should verify that the TiVo is on the -3.5db leg of the splitter and not the -7db leg.

    Where are the 3 outputs of that splitter going?
     
  7. Jun 2, 2011 #1507 of 1597
    chris98891

    chris98891 New Member

    6
    0
    Jun 1, 2011
    I was mistaken, its only a two way splitter. It comes in from the wall, there are two 3.5dB plugs, one goes to the tuning adapter, and one goes to the tivo. the tuning adapter is then connected to the tivo via USB

    EDIT: had a breakthrough...some contractors hired by charter came out...and let me tell you...they were fantastic. he crawled through the crawlspace, climbed up the telephone poles in the back, and explored the attic diagnosing everything he could. he found an old splitter that we eliminated, and whatdya know, that -3.5dB was causing the issue. channels are perfectly clear
     
  8. Jun 3, 2011 #1508 of 1597
    Phantom Gremlin

    Phantom Gremlin New Member

    1,555
    0
    Jun 20, 2002
    Tualatin,...
    It could be that the splitter was simply defective.

    But don't assume that a non-defective splitter costs you exactly 3.5 dB (or anything even close). If you're e.g. now on an 860 MHz cable system and the old splitter was designed for 750 MHz (or even for 500 MHz), then at frequencies above what it was designed for the attenuation could have been much worse, 10 dB or even 20 dB.

    What that means is *some* of your channels would have worked well, while others would have been almost totally unusable. And that probably was what you were seeing. You probably still have some *analog* channels at low frequencies, and those would get through just fine with the old splitter. But many cable systems put HD channels on high frequencies. E.g. around here Comcast puts them at 560 MHz up to about 800 MHz.

    Around here, Verizon was much better than Comcast in terms of testing installed cable for signal strength characteristics. When I had FiOS installed, the guy had a portable meter which he used to check multiple frequencies at every single outlet. In contrast the Comcast guy didn't even have a meter with which to test signal strength.

    Alas, things were too good to be true, Verizon sold us out to Frontier, and eventually I'll have to switch back to Comcast.
     
  9. Breeze

    Breeze New Member

    8
    0
    Mar 16, 2003
    Hi guys,

    I have an S3 with a WD extender and 2 S-Cards with Tuning adapter from Cablevision. I've had pixelation issues in the past that seems to have improved much in the last year (which I presumed was probably from a firmware update of the TA).

    However, I still have occasional pixelation issues where the picture is garbled and I lose a couple of seconds of my program. This may happen once or twice during a 1 or 2 hour recorded program.

    Can anyone tell me what most likely is causing this? Is this due to the S-Cards and I should switch to M cards? Or is it some other issue with my Tivo itself?
     
  10. Aug 5, 2011 #1510 of 1597
    SCSIRAID

    SCSIRAID Active Member

    2,321
    0
    Feb 2, 2003
    Vero Beach, FL
    It could be due to HDD or it could be due to cable signal quality. It could also be coming directly from the cable company (a breakup in the stream they receive from the provider).

    To explore signal quality tune a live show. Go into DVR Diagnostics and look at the tuner stats for the channel number you have tuned. Look at Signal Strength, SNR and the RS Corrected and Uncorrected statistics. Signal strength should typically be between say -5 and +2... not hard and fast but just typical. SNR should be 34 or higher. RS Uncorrected should be 0 or a very low number. Nonzero RS Corrected is ok but if it is large or incrementing quickly then you have a clue that your signal sucks. Then go back to live TV and watch it. When you see a breakup jump back to DVR Diags and see if the RS Uncorrected number jumped up. If it did... the TiVo encountered uncorrectable errors in the stream that were very likely the cause of your pixelation.

    DVR Extenders are notorious for causing problems... so as the previous poster indicated... HDD's can definitely cause this kind of problem too.

    Do you have a second DVR... TiVo or Cablecompany POS... or have a neighbor with one? If so, record the same show between the two and then watch on your TiVo and note where the breakups are. If the other DVR has the breakup at the same place.... its the cableco's problem. Garbage In Garbage Out. This is much more common than you might think.
     
  11. Aug 5, 2011 #1511 of 1597
    richsadams

    richsadams Active Member

    8,893
    2
    Jan 4, 2003
    Did you notice that the post is almost two months old? Not sure if he got it fixed or not and your info is certainly spot-on for anyone that happens by. However the thread was bumped by a spammer yesterday (post since deleted) and may be why it popped up on your radar. Just sayin'. ;)
     
  12. Aug 5, 2011 #1512 of 1597
    SCSIRAID

    SCSIRAID Active Member

    2,321
    0
    Feb 2, 2003
    Vero Beach, FL
    Ahhh... Nope, I didnt notice that. Thanks!
     
  13. Aug 7, 2011 #1513 of 1597
    Breeze

    Breeze New Member

    8
    0
    Mar 16, 2003
    Thanks SCSI. I was indeed still waiting for an answers.

    My Signal strength, depending on channel, is anywhere from 80 to 100. You said it should be between -5 and +2??? I figured 100 was the best?

    SNR is typically around 36 dB

    RS uncorrected is typically 0

    RS corrected is typically 0 or 2

    I don't typically notice these issues during live TV. It seems to occur more on taped shows. Which leads me to believe that it was more likely an hdd or extender issue.
     
  14. Aug 7, 2011 #1514 of 1597
    SCSIRAID

    SCSIRAID Active Member

    2,321
    0
    Feb 2, 2003
    Vero Beach, FL
    The signal strength numbers I quoted are available in Tuning Adapter Diags. Sorry bout that..

    The other numbers from DVR diags sound great.

    As to recordings vs live... TiVo always plays out of the buffer on the HDD so there isnt much difference betweeen live and recording playback.
     
  15. Nov 5, 2011 #1515 of 1597
    AVSman

    AVSman Member

    37
    0
    Mar 17, 2006
    Seattle, WA
    Hi all,

    We have a Series 3 using cablecards (Comcast cable in Seattle, WA). We bought it the first day it came out, so it&#8217;s over 5 years old. Over the past few weeks we&#8217;ve been getting more and more pixilated video/garbled audio. I followed TiVo&#8217;s HD pixilation diagnostic instructions, and I saw tons of RS Corrected and RS Uncorrected errors on each tuner when using cablecards (tens of thousands of errors).

    Here are the troubleshooting steps I&#8217;ve gone through so far:

    &#8226; Manually rebooted (unplugged, waited 15 seconds, plugged back in) &#8211; no change
    &#8226; Got different cablecards from Comcast &#8211; no change
    &#8226; Kickstart 57 &#8211; no change
    &#8226; Kickstart 54 - All S.M.A.R.T. tests passed

    I've noticed over the past year or two the occasional cablecard error. So, before I bothered checking wiring or swapping out coaxial cables, I thought, &#8220;I wonder if the problem occurs on unencrypted QAM?&#8221; I removed the cablecards, ran a channel scan, and the picture and sound are great &#8211; zero RS Corrected and RS Uncorrected errors on both tuners! This leads me to believe that some component in the cablecard pathway inside the TiVo is the problem, since a different set of cablecards had the same issue, and unencrypted QAM looks great.

    Has anyone encountered this before? Is there a certain component that I could swap out from a working Series 3 (bought from eBay or Craigslist)? Our Series 3 has lifetime so I&#8217;d like to keep it working. I haven&#8217;t soldered anything in 20 years, but I&#8217;m willing to give it a try, if necessary. :)
     
  16. Nov 5, 2011 #1516 of 1597
    SCSIRAID

    SCSIRAID Active Member

    2,321
    0
    Feb 2, 2003
    Vero Beach, FL
    What are the signal levels and SNR for each tuner while you are seeing pixelation?

    The Error stats are coming from the demodulator which is 'before' the cablecard so I wouldnt expect the issue to be cablecard related.
     
  17. Nov 5, 2011 #1517 of 1597
    AVSman

    AVSman Member

    37
    0
    Mar 17, 2006
    Seattle, WA
    I just performed another test. Viewing unencrypted QAM (without the cablecards), I saw the following stats:

    Channel 4-1
    Signal Strength: 95 - 100
    SNR: 35dB
    (no RS errors)

    Channel 16-1
    Signal Strength: 95 - 100
    SNR: 35dB
    (no RS errors)

    I then re-inserted the cablecards and viewed the same channels:

    Channel 104 (this is how Comcast maps 4-1)
    Signal Strength: flips between 95, 86, and 0
    SNR: 35dB
    (lots of RS errors)

    Channel 106 (this is how Comcast maps 16-1)
    Signal Strength: flips between 95 and 0
    SNR: 35dB
    (lots of RS errors)

    I'm consistently getting errors only using the cablecards. Unencrypted QAM continues to be fine. I would blame the cablecards, but this has happened now with two different sets.

    :confused:
     
  18. Nov 5, 2011 #1518 of 1597
    SCSIRAID

    SCSIRAID Active Member

    2,321
    0
    Feb 2, 2003
    Vero Beach, FL
    Are the indicated frequencies and Modulation the same between clear QAM (16-1) and with the cablecards in place (106)? The SNR's and signal levels are fine for the clear QAM... but you are right... something fishy is going on.

    Do you use a Tuning Adapter? If so.. is it in place for both tests (with and without cablecards?)
     
  19. Nov 6, 2011 #1519 of 1597
    AVSman

    AVSman Member

    37
    0
    Mar 17, 2006
    Seattle, WA
    Yes, the frequencies and modulation are the same between the clear QAM and using the cablecards.

    No, we don't use a Tuning Adapter. (And thanks for your replies, by the way!)

    If anyone has any idea as to what component might be the culprit, I'd love to hear it. I'm not looking forward to duplicating all of our season passes using manual recordings! :mad:
     
  20. Nov 6, 2011 #1520 of 1597
    SCSIRAID

    SCSIRAID Active Member

    2,321
    0
    Feb 2, 2003
    Vero Beach, FL
    Wow... This is a wierd one. One thing you could try is attenuation. If you have a 4 way splitter and can connect thru it that would drop signal level 7db. If you have a 2 way, that would be 3.5db. My thought is that you may be on the edge of tuner overload but I am really 'reaching' here as I dont see what the cablecards would have to do with it. At least it would be one more thing off the table.
     

Share This Page