Diagnosing Pixelization – Hard Drive or Tuner?

Posted on April 9th, 2008, by Michael

Pixelization is definitely one of the most common problems that TiVo users encounter. The question is, is this blockiness of images due to problems with the tuners or with the hard drives?

Both components can cause pixelization, but the problems act a bit differently in each situation. Of course, diagnosing the problem correctly is essential to fixing the problem . . .

Our best procedure for differentiating between the two problems is this: replay the bad segment. If the pixellization recurs exactly as it did the first time (watch carefully, and try it again if necessary) then the problem is almost definitely with the tuner. If the pixellization changes when you replay the segment, then you likely have a bad hard drive.

While you may think that a bad spot on a hard drive should cause the same pixellization to happen during a replay, our experience shows differently. If a hard drive has an error on the surface, or any other problem feeding data to the processor, then the results are different each time. But if pixelization is recorded to the drive, then it replays the same way each time.

Also, a DIRECTV TiVo often will have just one bad tuner, not two, so if you see pixelization, you can try removing one of the satellite cables from the back to see which tuner is pixellating. If you are watching a show and pull a cable, the picture will either disappear or you will see “Searching for signal on Satellite” with the pixellating picture still showing. If you continue to see the picture, then the tuner you are watching is the one that you did NOT pull out. If you are seeing pixelization only on one tuner, but not the other, then you have a bad tuner.  (Please please NEVER move the TiVo while it is on. Also, take note that you can switch tuners on a DIRECTV TiVo by pressing down on the circular directional pad.)

So how do you fix this? If you have a bad drive, that’s easy. We have replacement, pre-formatted TiVo hard drives for every model TiVo. Be sure to get a replace kit in this situation.

If your tuner is bad, then we can repair tuners on DirecTV TiVo units, and we also have replacement DirecTV TiVos still. If you have a standalone TiVo, and you don’t have lifetime service, it’s probably better to consider a new unit. See our list of new TiVos.

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  1. DIRECTV TiVo Tuner Problems at WeaKnees Blog Says:

    […] could be a drive or a bad tuner, and we previously wrote about ways to diagnose the source of a pixellating DIRECTV TiVo. If you rewind, the pixellation is in the same place […]

  2. Laurie Bennett Says:

    “If your tuner is bad, then the fix isn’t as clear-cut. We can repair tuners on DirecTV units, and we also have replacement DirecTV TiVos still. If you have a standalone TiVo, and you don’t have lifetime service, it’s probably better to consider a new unit. See our list of new TiVos.” Can you tell me why you would recommend a new unit rather than a cheaper replacement tuner?

  3. Roger Knopf Says:

    One other possibility – if you have a directional OTA antenna that is not aimed correctly for the station you are viewing, or the signal is too weak, it will pixelate and look like a bad tuner.

  4. Susan Says:

    What if the pixelization is on certain channels only? Directv has been truly awful in their customer service and said I have to pay for a service call and buy a new receiver. Once I canceled certain channels (HBO), the pixelization is gone for the most part. But i miss HBO…

  5. Michael Says:

    This is a good question, and we’ve gotten it a lot recently:

    Why is there pixellation only on certain channels, and what does that mean?

    In our experience, we often see boxes here that have pixellation on some channels, but other channels look fine. Our theory is that the chips on the motherboard that have damage have problems with specific transponders. So there’s pixellation on any channel coming through that specific transponder, but the next channel may be on a different transponder, so it comes in perfectly.

    In any event, our motherboard repairs of failing tuners to fix the problems when they’re only on certain channels.

    Further, if you’re sending in your unit, and your problems are limited to certain channels, please note that in your order so that when can see the problems when we do our pre-repair testing.

  6. manuel Says:

    I am seeing this problem on one tuner with the same channels. I agree that the problem may be with certain transponders.

    I am considering purchasing a replacement box, but I have a question. Will the drive from the malfunctioning system work on the new system? Can I simply take it out of one and in to the other without any problems?

    Please let me know, I am looking for a workable solution as soon as possible.

  7. Tom Says:

    I have a TIVO series 3 that only pixilates at two megahertz frequencies. There are several channels on I think it is 567,000 and one HD channel on 561,000. All other channels work fine. These channels work fine in analog through the cable but do act up in the SD or HD channel. The cable company has tried many many things but the problem remains,,,TIVO keeps blaming the cable company signal. Any suggestions?

    thanks

  8. Jackie Says:

    I have been having pixelization problems for years–but with cable (Comcast). I have always assumed it was a cable problem and have had them reset my signal, come check my cables, etc. And the problem returns. So you are saying it could be the hard drive on the Tivo box itself? Hmmmmmmmmmmmmmmm.

  9. Roger Says:

    My problem is pixelization (on only the bottom 10% of the screen) PLUS a “push up” of the screen so that the top 10% of the program disappears whenever I fast forward or backward. The pixelization disappears whenever I “reset” by going to the Tivo menu then back to either the current unrecorded “live” broadcast or to something recorded. Hitting the fast forward or backing-up causes the problem. Everything seems to be recording fine and the play fine as long as I don’t try to skip a commercial.

    This problem does not occur when I patch the FIOS box directly into the TV monitor and eliminate the Tivo. Of course, so does the ability to jump around the commercials.

  10. Bob the Dissenter Says:

    Having a relative who works at DTV, I do know that years ago they ‘optimized’ bandwidth by increasing channel compression to allow for more channels (and therefore profit). This may also be a factor when you see a fast pan at long
    camera focal lengths.

    Good luck finding out the compression ratios and methods employed, but then
    we threw away our vinyl for mp3 technology so no one really cares anyway.

  11. Bob Church Says:

    I know this sounds like something you’d never do, but you might be unpleasantly surprised. When disconnecting an input to see which Satellite you’re on don’t forget to make sure you aren’t watching buffered tv. It’s especially easy to do if you’ve been bumping back to test tuner vs hard drive.

  12. S Lawrence Says:

    Pixellation can also be caused by a bad LNB. I had three service calls and all cables and other components replaced (including a multiswitch) before a technician decided to change the LNB. Problem solved – after 2 months of unwatcheable HD reception.

  13. Lance Says:

    I had pixelation that started on a few channels and eventually appeared on all channels. I switched to my tv’s internal tuner (I just get my signal over the air) and the pixelation stopped. I rebooted my TiVo by pulling the power cord, waiting about 30 seconds, and repowering. This seems to have resolved it. In short – reboot. It’s the first and easiest thing to try to solve this.

  14. R Engle Says:

    My DVR is Philips DSR 708. Pixellation occurs at a minimal level on numerous channels, but is severe on one of my local channels, Sat 2, channel 5 on Directv also local channel 5 KING TV. The pixellation occurs at the same spot when replayed, which could indicate a bad tuner. However, when I switch the satellite cables, pixellation continues on both tuners at the same severe level on Sat 2, channel 5. Audio is also lost during the same pixellation segments.
    This problem has been ongoing for 6+ months. The Sat signal strength is steady, between 85 to 95 on all transponders.
    I’d like to send my DVR in for flat-rate repairs, but can not tell if it’s a hard drive problem or tuner problem … or completely something else (bad LNB?).

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