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TiVo HD DVR - No Video Output

Discussion in 'TiVo Series3 HDTV DVRs' started by hankinsohl, Oct 23, 2013.

  1. unitron

    unitron Active Member

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    With no drive attached it'll usually just sit there on the welcome screen until the cows come home.

    If the drive is attached, but there are problems with the motherboard communicating with it, that will produce the uniform gray screen, or it will cause an endless cycle of reboots, depending on exactly what the problem is.
     
  2. unitron

    unitron Active Member

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    That's almost always a no-no with switch-mode power supplies like the TiVo uses.

    Switch-mode supplies need to have a sufficient load attached.

    You can run it with the motherboard connected and the drive disconnected for short periods for test purposes, but try to avoid the other way around, and definitely don't do it with both the motherboard and the drive disconnected.


    That's definitely more like it, although it's possible that the DC reading is in the ballpark but at least one of the outputs has too much AC "ripple" in it.


    Well, some kind of video seems to be getting sent out.

    But that pulse in the LED on the front leads me to suspect power supply trouble before motherboard trouble.
     
  3. unitron

    unitron Active Member

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    By component you mean the Red, Green, Blue plug trio, correct?

    What you've got there looks like a video sync pulse problem--that's the signal that tells the TV when to start sweeping each line across the screen--it's not putting the video signal result on the right place on the screen at the right time.

    If you're TV has a composite input (the yellow jack), connect the TiVo's yellow jack to that and see what you get.

    If you don't have a cable with yellow RCA plugs at each end, use one of the Red,Green,Blue ones--electrons don't have different colors.
     
  4. unitron

    unitron Active Member

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    I'm pretty sure I read somewhere that expanders need to be attached when you go through the "divorce" process.

    But let's concentrate on getting a good welcome screen without the drive attached first.
     
  5. unitron

    unitron Active Member

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    I've got that same 3Y board in one of my 652s.

    There are 9 caps near the big heat sink that are possible suspects.

    I'll try to get a list of them posted here this evening.

    In the meantime look on both sides of that heat sink and check all 9 for absolute flatness on top and no bulge out of the plug in the bottom. We might get lucky and not have to replace all 9.
     
  6. hankinsohl

    hankinsohl New Member

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    When I hook up my TiVO to the yellow composite video jack, here's what the output looks like:

    [​IMG]

    Note: On first booting up, the screen is pitch black. After a few seconds, the squiggly line output appears as shown above. Also note that I haven't connected the cable TV cable or an antenna.

    And here's a picture of the capacitors closer to the power cable:
    [​IMG]

    Unitron - Since my re-measured voltages all appear to be within tolerance, doesn't that rule out the power supply? Originally I was measuring voltages by unplugging the power cable; I repeated the measurements (see the "Correction to Voltage Measurements" post above) with the power cable attached to the motherboard and the voltages look OK.

    Thanks once more for everyone's help. Does this seem to be a fried motherboard?
     
  7. ciper

    ciper New Member

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    It has been my limited experience that those are the ones to fail first. However they look ok in that picture. Here are some good comparison images http://en.wikipedia.org/wiki/Capacitor_plague

    That is usually the case but one time I had forgotten to attach the power cable to the drives and it would show the welcome screenthen switch to a solid grey screen (over component and HDMI)

    But yes his out of sync image is not normal

    It does put an extra load on the power supply but that should only happen on startup. I'd argue that running two 7200 1tb drives in my Tivo for years was more of a burden on the power supply than topping up these caps will be. If the load pulled enough to "empty" the capacitor then the sag on that line would also get bad with the original caps right? My understanding of the situation - Lets say under normal conditions the 2200uf was normally alternating between half to full capacity. If nothing else in the unit has changed then the 3300u should then alternate between one third to full capacity and the draw during normal use would be nearly equal.
    I'd rather the capacitor do its work than have something overdraw or brownout that line.

    My other motivation for overspecing them is that if you have two identical capacitors at X uf and 1.5X uf the 1.5X uf will have lower ESR by default.
     
  8. hankinsohl

    hankinsohl New Member

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    >> But yes his out of sync image is not normal
    Any thoughts on how I might fix this out-of-sync image issue? Or is it a fried motherboard and I'm out of luck.
     
  9. hankinsohl

    hankinsohl New Member

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    I've made a video of the pulsing green light on the front of my TiVO. It can be seen here:
    http://www.youtube.com/watch?v=yT7NzhXoJig&feature=youtu.be

    The youtube video really exaggerates the pulsing - in real life it's much more subtle and the pulses are very fast, maybe 1/10th of a second apart or so.

    I also tried to check for AC voltage along the power cord using my multimeter. I got zero AC volts on all the power lines (yellow, red and orange).

    Finally, just to mention this once more, the format button on the front of my TiVO doesn't do anything - none of the format indicators light up at all.

    So, given the above, and noting that the DC voltages seem to be in spec, any guesses as to what's wrong? Might the power supply be bad and cause all of these symptoms and yet be within spec with respect to DC voltage output? Or is this a sign of probable motherboard failure somewhere.

    Thanks once more for everyone's help.
     
  10. ciper

    ciper New Member

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    Can someone suggest an easy way for him to read the logs? Perhaps a boot CD that is known to be able to mount partition 9? We could have him check the last entry now, then try to boot his Tivo for a while and check the log again. If the log has no changes we know its not getting anywhere.
     
  11. hankinsohl

    hankinsohl New Member

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    Thanks Ciper. I looked a bit on the Internet for this - couldn't find anything. Also complicating maters is that the data may have been striped to the drive expander drive which was previously connected - i.e., all of the data currently on my TiVO drive might be totally unreadable at the moment.
     
  12. mr.unnatural

    mr.unnatural Active Member

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    Ellicott...
    At this point you might want to consider getting a replacement Tivo. Since yours has lifetime on it I'd call Tivo and see if you can transfer the lifetime to another unit. If they will do that for you then I'd head to ebay and pick up a used non-lifetime Tivo. You'll probably pay less for the Tivo on ebay than whatever parts you intend to replace in your unit.

    With the exception of the motherboard, you could get a used Tivo HD and cannibalize it for parts if Tivo won't allow you to transfer the lifetime service.
     
  13. dianebrat

    dianebrat I refuse to accept your reality TCF Club

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    boston'ish
    I'm still voting power supply, just because it meters ok doesn't mean it is ok, if you'd used an oscilloscope that would show you how good the power really is.
    I'd consider having Weaknees repair it, or putting an original HD in it and calling Tivo to see if they'll give you a deal on a new unit.
     
  14. sfhub

    sfhub Active Member

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    Is there a reason mfslive wouldn't fit the bill? Partition 9 is an ext2 formatted partition, right?
     
  15. hankinsohl

    hankinsohl New Member

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    I contacted weakNees to see whether or not he thought my TiVO can be fixed. His opinion is that it cannot be repaired. It seems that the rapidly pulsing green light on the front of the unit indicates some sort of motherboard issue that cannot be fixed.

    I contacted TiVO and they refuse to transfer my lifetime subscription unless I purchase a replacement unit from them for about $350.00 or so. Since you can get a used TiVO HD with lifetime subscription off EBay for about $230.00, TiVO's replacement offer isn't appealing.

    Thanks everyone for your suggestions and help. I think I'm simply going to dispose of my TiVO.
     
  16. unitron

    unitron Active Member

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    Did weaKnees use any particular technical terms that might give us a clue what the problem is?

    If you're going to pitch it into a landfill, how about I pay shipping and you send it to me to take a shot at?
     
  17. hankinsohl

    hankinsohl New Member

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    @Unitron
    I was going to drop off my TiVO at Staples for recycling but if you'd like to take a shot at fixing it that would be great. I sent you a private message to work out shipping details.
     
  18. unitron

    unitron Active Member

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    Apr 28, 2006
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    For the benefit of future searchers, by co-incidence I found out about a guy in Australia who does TiVo repair and on his FAQ page

    http://kingey1971.wix.com/tivorepairs#!faq/c1yws

    there was this

    So, no joy for the OP, but at least we now know more than we did.
     
  19. unitron

    unitron Active Member

    16,390
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    Apr 28, 2006
    semi-coastal NC
    Well, instead of the landfill the machine went to me.

    It turns out the power supply is apparently okay because swapping in a known good one made no difference.

    The green light on the front doesn't blink like it was doing to him--I have no idea if that's related by some bizarre reason to its cross-country trip or not.

    I hooked the composite (yellow jack) output to a composite input on a little battery operated black and white portable of the type that was nice to have during hurricanes before the OTA switch from analog to digital, and by fiddling with the vertical hold was able to see that it's actually outputting the initial welcome screen, but I'll need a different set with externally accessible horizontal controls as well to get closer to a stable picture, so apparently there's something wrong with whatever establishes the vertical and especially horizontal sync pulses.

    Unfortunately, without a schematic or service manual I'm not sure I can make any further progress.
     
  20. squint

    squint New Member

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    Jun 15, 2008
    If I get an IR rework station in the future, I could try re-balling the CPU or moving it to a donor motherboard.
     

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