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Tivo HD Pixelation Troubleshooting

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

  1. Nov 6, 2007 #341 of 1597
    BigFrank

    BigFrank New Member

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    Sep 21, 2006
    I too have been having problems (since about 9.1) with freezing/fast forward and even more notably occasionally it wont record a show - claiming signal was lost.

    Yesterday it was recording a show (probably about 2/3 of the way through - i actually saw the show playing so it had good video for a while) and when I looked for it later on it was nowhere to be found. It was listed in the to-do-list as not recorded due to lack of video signal!!! Even if that were so, why did it delete the show after it had a significant chunk recorded?
     
  2. Nov 7, 2007 #342 of 1597
    esmtexas

    esmtexas New Member

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    Mar 8, 2007
    I have FiOS and have always had three HD channels with so much pixel... we cannot watch. verizon changed cables even between a Verizon HD box I had, still no change. I pretty much dont watch those three HD channels. Now, since 9.1 we are getting random/multiple pizelization on MANY SD channels.

    This MUST be a TiVo issue, not FiOS since the problem got worse with the upgrade to 9.1. Is it time to throw out TiVO if they can't get this right? :thumbsdown: :mad:
     
  3. Nov 8, 2007 #343 of 1597
    Daxel

    Daxel New Member

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    May 13, 2002
    So... I fixed the problem. All of the problems.
    If you go to the diagnostics of your cards, watch the signal strengths. If they are not 90-100, you might get pixelization and skipping. Fortunately for me, there is a good AV shop near my house, and I got a long very high quality coax cable. I connected it to the FIOS box and my Tivo, and watched as the signal went from 62-80 (fluctuating) to 95 or 100 on HD. I do not know why the cable I had already run in the house wasn't good enough, but it wasn't. I re-ran high quality cables with compression fittings (yes, the good ones with the $40 tool to apply them). I have a single signal booster at the FIOS box now that splits the cable into 3 lengths. 1 to the cable modem, 1 to each HD Tivo. No other splitters, all cables under 100' in length. I watched and recorded from the channels that ALWAYS had problems last night, and they were completely clean and clear. I watched the signal strengths, and they remained constant. I was talking to one of my neighbors, and although he does not have a HD Tivo, his HD was doing the same thing before he also re-ran cables about two months ago (should have talked to him sooner).
    I don't know if everyone's problem can be fixed in this matter, but it cannot hurt to try. By the way, the attenuators from a post further up were totally the wrong thing for me. However, if you are overamping the signal, you might need an attenuator to bring it back in line.
     
  4. Nov 8, 2007 #344 of 1597
    btwyx

    btwyx Substantive Member

    11,331
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    Jan 16, 2003
    Mountain...
    There seems to be some real crap out there sold as co-ax. I just installed a whole bunch, it got buried in the walls when we were remodelling. Some of them, including all the ones run to the TiVo were just crap, and wouldn't pass a signal. If I turned the amplifier up to +15db I get a detectable signal on the TiVo, if I run a good cable directly from the cable entry to the TiVo I get strengths of 100.

    With the cables buried in the wall it makes it very difficult to replace the cable.
     
  5. Nov 8, 2007 #345 of 1597
    richsadams

    richsadams Active Member

    8,893
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    Jan 4, 2003
    Thanks for the detailed account of your coax cable experience. I've posted comparable advice and received a good deal of push back for some reason...that it had to be TiVo, couldn't be anything else. TiVo demands a good, clean signal to work properly.

    Our story was quite similar. Comcast had run new coax and we had even purchased some new coax from one of the bigger department stores which turned out to be of terrible quality. Once we had invested in some decent coax cable (from Fry’s) any macroblocking we had on our S3 was almost completely eliminated. There will always be slight problems from the source but the difference was remarkable.

    It’s probably not a fix for everyone, but it’s a good place to start.

    Thanks again! :up:
     
  6. Nov 8, 2007 #346 of 1597
    Phantom Gremlin

    Phantom Gremlin New Member

    1,555
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    Jun 20, 2002
    Tualatin,...
    The cables Comcast installed for me were very high quality with uniform compression fittings (not the inferior hex crimp).

    Doubtlessly the quality varies from city to city and from installer to installer.
     
  7. Nov 8, 2007 #347 of 1597
    richsadams

    richsadams Active Member

    8,893
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    Jan 4, 2003
    Good point, and to be fair Comcast only replaced the coax from the wall to TiVo. We ended up replacing everything, so the short amount that they had replaced may have been fine. The aggravating part was that we thought it was a TiVo problem for a while as well.

    We replaced a Comcast (POS) HD DVR with the S3...and immediately saw macroblocking and audio issues. The Comcast tech said the signal was perfectly fine...based on his measurements and the fact that there was no macroblocking on the Comcast DVR. Once we replaced the rest of the coax the problem was resolved, even though they had said the signal was fine. It may have been acceptable to the Moto DVR (and Comcast), but it obviously wasn't adequate for TiVo.
     
  8. Nov 10, 2007 #348 of 1597
    PieThief

    PieThief New Member

    7
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    Apr 1, 2007
    I am still having problems with my S3 + Fios.

    I've had FIOS TV for a couple years, at first we had their horrible STB. However, while the UI was bad, the picture/audio was perfect 100% of the time. We purchased a S3 because I missed my S2 but and wanted Tivo while recording HD.

    Had a lot of problems with 'pixelization' or whatever. It's so difficult to know by what people type if we're describing the same problems. Basically, it looks like the picture someone posted a few pages back in this thread and it's accompanied by corresponding audio drop outs. However unlike people who claim it happens a couple times an hour, with us, if it's happening it's happening every second or three, rendering a show completely unwatchable (and unlistenable).

    We have run the gamut of things. Verizon testing signal strength. ("Perfect"). Resetting cable cards. Replacing cable cards. Replacing ONT box outside the house. Had the S3 tivo replaced for another one (same issue.)

    The interesting thing is I discovered pretty early on that if I removed the Tivo from the setup and plugged the cable cards directly into my TV and just tuned from the TV, the signal was perfect 100% of the time. So, it's some issue with TiVo, or TiVo + FIOS but I'm not sure what. I just know that I've had perfect signals directly tuning through my TV with the cable cards, or the STB from FIOS, but plugging the same cards into the TiVO leads to crap.

    Like some people, it sure seems that this happens a lot more during must see TV. I have totally missed this season of Heros because the first episode was completely fubar. The problem has gotten much worse and it seems like for the last week or so, nearly all channels are affected and I have just stopped watching TV.

    I'm just angry because I paid $699 or whatever for the S3, then another $200 to transfer my lifetime to it, and I can't watch TV... or it's so horrible that I don't want to. I'm not a super uptight tv wanker either, if something occasionally skips or whatever, that's fine. But if I cannot watch one complete question being asked by larry king without the audio & picture dropping out 3 times that is unacceptable.

    I've gotten to the point of just not trying anymore because I just don't have the time available to dedicate more half days off work to fix this problem. I am practically to the point of calling comcast up and trying to see if I get the problem with them, but I love the FIOS TV package (in theory) so much I really want to be able to watch it.
     
  9. Nov 10, 2007 #349 of 1597
    Daxel

    Daxel New Member

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    May 13, 2002
    PieThief - what is the signal strength on the cable cards when they are in the Tivo?
     
  10. Nov 10, 2007 #350 of 1597
    AbMagFab

    AbMagFab What happened, TiVo?

    3,638
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    Feb 5, 2001
    Have you tried the multiple suggestions of attenuating the signal? This has seemed to work for almost everyone who thinks they have a good signal - it's usually too strong with FIOS.
     
  11. Nov 10, 2007 #351 of 1597
    bkdtv

    bkdtv New Member

    7,902
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    Jan 9, 2003
    DC Metro Area
    As noted above, the pixelization on FiOS has an easy fix. You just install an attenuator.

    Calling Verizon rarely does any good, because they take one look at the signal and say it is perfect. But in many cases, a "perfect" signal for Motorola boxes is too strong for the TiVo.

    I'm starting to think we make this information a sticky. People call TiVo, call Verizon, request RMAs, schedule FiOS appointments, etc and that is all a waste of time. The box is not defective and the FiOS signal is perfectly fine for the Motorola boxes, but too strong for the TiVo. In most cases, the one and only fix is to screw a $2 attenuator onto the end of the cable. This fix takes approximately 60 seconds.
     
  12. Nov 10, 2007 #352 of 1597
    bkdtv

    bkdtv New Member

    7,902
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    Jan 9, 2003
    DC Metro Area
    Pixelization with Verizon FiOS: How to Fix

    Background

    FiOS uses several different ONTs which provide an average signal level of +12dB to +18 dB to +24 dB. Output from the most widely used ONT (Motorola 612) is +18 dB on most channels. Output with older installations (Motorola 611) is up to +24dB.

    For some reason, the output on many ONTs (or some COs?) is not linear. The output might be +14dB to +16dB on most channels, but +20 dB on others.

    Verizon installers are instructed to add an attenuator to reduce the signal down to +5 dB. Some do, some don't, as the Motorola STBs and DVRs tend to work fine with mosts signals of +10 dB or less.

    The Problem

    Installers are taught that a signal level of +5dB is excellent. That signal is fine for the Motorola boxes, but in many cases, it is too strong for the TiVo.

    With a signal level of +5dB, the majority of channels will be fine on the Tivo, but many may exhibit intermittent pixelization. On these channels, RS Corrected and RS Uncorrected errors increment rapidly, SNR fluctuates, and signal strength fluctuates between 100 and a lower number (such as 50).

    Even with a signal level of +0dB, some channels may exhibit intermittent pixelization. In my experience, 90-95% of FiOS channels are fine with a signal level of +0 dB, but that signal level is still too strong on perhaps 5-10% of channels.

    I attribute this to non-linear output from the ONT -- most channels may be +0dB but others in different frequency ranges may be +5dB higher (or more). It is these channels with higher signal levels that exhibit pixelization. FiOS uses the same frequency ranges for locals, RSNs, and other cable channels on every system across the country. It is common for the local HD channels to be in the frequencies with a higher signal level.

    More often than not, calling Verizon FiOS support is not a solution, because installers take one look at the +5dB signal level and conclude that the signal is fine -- just as they are trained to do. Verizon installers do have attenuators, but they don't attenuate the signal further because they are trained on the requirements of the Motorola boxes, not the TiVos.

    The Solution

    The solution is to further reduce signal strength to -6dB or lower by adding an attenuator to the end of the coax cable. This does not affect the FiOS channels with lower signals levels, but it eliminates the pixelization on FiOS channels with higher signal levels. It takes about 60 seconds to install an attenuator.

    Steps to Fix

    1. Order a pack of attenuators. These screw on to the end of the coax.

      http://www.smarthome.com/7800.html

    2. Find a channel with pixelization.

    3. Once you've found a channel with pixelization, open Settings -> System Information -> Diagnostics. With this screen, you can monitor your SNR and number of RS Corrected and RS Uncorrected errors.

      Your goal is to completely eliminate the RS Uncorrected errors and the fluctuation in the SNR. A few occasional RS Corrected errors are fine; it is the RS Uncorrected Errors that indicate pixelization.

    4. Disconnect the coax cable from the TiVo.

      Note the process of disconnecting and reconnecting the coax will result in a lot of RS Uncorrected and RS Corrected errors, but don't worry about that. Only worry about errors that increment after the cable is firmly connected.

    5. Most seem to require -10dB to -16dB of new attenuation. I would start with -16dB. Screw one -10dB attenuator and one -6dB attenuator onto the end of the coax cable. Then reconnect the coax back to the TiVo.

    6. Is the problem fixed? Wait 60 seconds. Have the RS Uncorrected errors stopped incrementing on the Diagnostics screen?

    7. If not, disconnect the coax again and repeat step five using one -10dB attenuator and one -2dB attenuator.

      Is the problem fixed? Wait 60 seconds. Have the RS Uncorrected errors stopped incrementing on the Diagnostics screen?

    8. If not, disconnect the coax again and repeat step five using a single -10dB attenuator.

      Is the problem fixed? Wait 60 seconds. Have the RS Uncorrected errors stopped incrementing on the Diagnostics screen?

    9. If not, disconnect the coax again and repeat step five using a single -6dB attenuator.

    10. By now, the problem will be fixed.
     
  13. Nov 10, 2007 #353 of 1597
    PieThief

    PieThief New Member

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    Apr 1, 2007
    When it's working it's rock solid anywhere between 95-100, usually in the 98-100 range. When it's messed up it's pinging between these values and usually something in the 80's or 70's. When I was trying to solve this issue months ago I did notice the problem channels appeared to be in a certain frequency range (which makes sense given the explanation I'm reading here).

    If I recall, the Verizon tech said our signal was +0db. I'm definitely willing to try anything though and although I missed the attenuator post, I am going to stop up at Fry's and see if I can buy some to try out tonight.

    My display for corrected / uncorrected errors both display "Not Available" or something to that effect. So, I'm not sure that information will be available to me as I try the attenuators. I do see the display for SNR and it is showing values in the 30s (usually pinging around a little bit.) Is there a typical value that is 'good' for SNR on TiVo?

    I will post an update if I find out more. I did stop by Best Buy and picked up a TiVo HD just to try it out and see if the problem happened on that box as well.
     
  14. Nov 10, 2007 #354 of 1597
    bkdtv

    bkdtv New Member

    7,902
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    Jan 9, 2003
    DC Metro Area
    If you have software 9.x, you should see that information on the Diagnostics screen. I'm not sure it was available on releases prior to that.
     
  15. Nov 10, 2007 #355 of 1597
    PieThief

    PieThief New Member

    7
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    Apr 1, 2007
    I hit Fry's and two separate Radio Shacks and struck out. I may have to order them online. Will post results when I get them.
     
  16. Nov 10, 2007 #356 of 1597
    SCSIRAID

    SCSIRAID Active Member

    2,321
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    Feb 2, 2003
    Vero Beach, FL
    You can use a splitter as an attenuator and do some testing till the 'real things' arrive. An 8 way splitter is basically an 11db attenuator.
     
  17. Nov 10, 2007 #357 of 1597
    richsadams

    richsadams Active Member

    8,893
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    Jan 4, 2003
    Agreed, this should be placed on its own thread as a sticky.

    Nice work! :up:
     
  18. Nov 10, 2007 #358 of 1597
    richsadams

    richsadams Active Member

    8,893
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    Jan 4, 2003
    Heck, I had a cheapo two-way splitter that was 8db. :mad:
     
  19. Nov 10, 2007 #359 of 1597
    SCSIRAID

    SCSIRAID Active Member

    2,321
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    Feb 2, 2003
    Vero Beach, FL
    It was marked at -8 per port? or was that its acutal effect? A 2way should be minus 3.5db. Sometimes they are labeled -4db.
     
  20. Nov 10, 2007 #360 of 1597
    PieThief

    PieThief New Member

    7
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    Apr 1, 2007
    I found many splitters and started putting them together. It did not help. I think I had two 3.5 splitters, a 7 splitter and an 11...

    But I did discover something interesting. When I plugged the TiVo HD in (the new one we picked up today) the signal was not messed up. I looked at the diagnostics and the signal strength is rock solid 100. Switch everything (coax, HDMI, cable cards) back to the S3 and it's 100->77->95->60->90->etc... the signal strength changes approximately once per second. I have found two channels that it's happening on really badly right now for S3, and I switch over and it's perfect with the HD. So I guess I'm going to have to call TiVo again. I'll watch for a little while longer with the new box to be sure but I haven't seen it mess up once yet.

    :(
     

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