I fixed my Tivo for $1.59

Discussion in 'TiVo Coffee House - TiVo Discussion' started by Floydian, Apr 14, 2011.

  1. Floydian

    Floydian New Member

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    Jul 16, 2009
    I just wanted to share a quick success story with my Tivo 24004A. It started rebooting itself and eventually just went to a solid blue screen with no lights on the front. Further diagnostic revealed the hard drive drive was not spinning up with IDE cable connected (but it was without, which I found very weird!) Some persistent research about this led me to inspect the capacitors on the power supply, one of which was slightly bulging (it was a 2200uF10v). I went to a local electronics store and purchased a replacement for $1.59, spent about 5 minutes soldering, and my Tivo has been successfully resurrected! Cheers to anyone who finds this information useful.
     
  2. mattack

    mattack Well-Known Member

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    Blue screen from the TV, right? Not from the Tivo? i.e. you're saying that the Tivo wouldn't start up -- but the drive would spin up?

    I seem to be having the same thing happening with my S3 -- which somehow coincidentally happened when I tried to upgrade my hard drive (after replacing another one that had suddenly died -- it spins up but doesn't show up).

    i.e. the fan & drive turn on, but no front lights on Tivo, no video output..

    That sounds similar to what you're referring to.
     
  3. unitron

    unitron Well-Known Member

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    "I fixed my Tivo for $1.59"

    Is that what they're charging for bullets these days? :)

    Seriously, make a note of all of the values (microFarads and Working Voltage) of the big capacitors on the power supply board, and then get High Temp, Low ESR replacements for each, cause if one went bad I'd be suspicious of all of them, and if you used a general purpose capacitor, like what you'd use in the older non-switching power supplies, it might not last all that long in its current role.

    Go to badcaps.net and read to learn about capacitor disease and why switching supplies need premium caps.
     
  4. unitron

    unitron Well-Known Member

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    Do you happen to own a Voltmeter or multimeter?

    Have you checked to be sure that you haven't partially dislodged a cable from the motherboard to the front panel?
     
  5. Floydian

    Floydian New Member

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    Jul 16, 2009
    Can't really say whether the blue screen was coming from the Tivo or the TV because when the Tivo is unplugged, it just passes through the cable box signal. But the hard drive was NOT spinning up as long as the IDE cable was connected. The rear fan was definitely spinning.
     
  6. Floydian

    Floydian New Member

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    Jul 16, 2009
    The original capacitor was a 2200uf 10v. I replaced it with a 2200uf 25v capacitor. Here is a link to the capacitor I bought:

    http://www.frys.com/product/6432722?site=sr:SEARCH:MAIN_RSLT_PG

    They don't have a very detailed description of the capacitor on there, but the following link does (it's the same part #):

    http://www.newark.com/jsp/search/productdetail.jsp?SKU=34P1071&CMP=AFC-OP&CMP=AFC-OP

    And here is a link to the manufacturers page with information about that line of capacitors:

    http://www.nteinc.com/capacitor_web/pdf/nev_neh.pdf



    It's been running fine for 24 hours now with the new capacitor so I'm not too worried about it exploding. I think the worst that will happen is that it will go bad again and I'll have to replace it again. My Tivo is cold to the touch. I'm not too sure how to find the ESR rating of this capacitor.. can you tell from the information linked above?
     
  7. trip1eX

    trip1eX imo, afaik, feels like to me, *exceptions, ~aprox

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    Nice job!
     
  8. unitron

    unitron Well-Known Member

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    NTE is a decent brand and you've got a good general use capacitor there. By getting a 25V instead of a 10 you probably got yourself a little leeway with regard to temperature, but with electrolytics it's not recommended to go any higher than that above the voltage to which the capacitor will actually be exposed.

    ESR is equivalent series resistance and is a part of the capacitor's overall impedence, and it's somewhat complicated, but if you're going to own consumer electronics you should go to badcaps.net and read up on it, since practically everything that doesn't use a wall wart these days has a switching type supply, and there doesn't seem to be any end to the capacitors made with the incomplete electrolyte recipe obtained by industrial espionage back in the '90s, so it's going to be an ongoing problem.

    I'm using an HP LCD monitor right now that someone left out for the trash. I replaced the big caps in the power supply with a set of them from LCDalternatives and it's working fine, but if a big brand name like HP can have the problem, most any brand can.

    You probably won't see ESR mentioned unless a capacitor is specifically being marketed as "Low ESR", in which case it'll also be rated for something like 105 or higher degrees centigrade (I miss Celsius) instead of 85.
     
  9. mattack

    mattack Well-Known Member

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    Do you mean the front panel *on the Tivo*?

    If so, I would STILL BE GETTING VIDEO OUT...?

    Again, plugging in the Tivo seems to be doing nothing EXCEPT powering up the drive (can feel it spin) and the fan at the back.. No other visual/noise/spark/smoke effects present..

    So it seems like the power supply is putting out "some" power, just maybe not to the motherboard itself.. But to me, that seems like it could mean I busted something on the motherboard itself rather than it being the power supply. I'm game for any easy fixes though (the ~$100 power supply from weaknees is one resort, but if that won't fix it, it's not worth it).

    I *did* do the low tech "unplug the big rectangular plug from the power supply to the motherboard and plug it back in", with no change. (Unplug/replug with main power unplugged of course.)
     
  10. unitron

    unitron Well-Known Member

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    The front panel to which I refer is the part of the Tivo at which you aim the remote control. It has lights and an InfraRed sensor and, on some models, an IR sender. There's at least one cable that connects all of that to the motherboard. Some people doing hard drive upgrades have dislodged or partially dislodged this cable from where it attaches. On some models powering up in that condition would fry some components on the motherboard. Even if you didn't damage anything, if you bumped the cable and it's no longer making full contact on all conductors, then at best you're going to confuse the motherboard somewhat when it goes through it's pre-flight checklist on bootup.

    So, check that cable. On both ends.

    It could also be that your power supply is still providing the +5 and +12 Volt lines which the hard drive and fan use, but there's something wrong with one of the other lines. There's probably a +3.3V line, and maybe one up around +30V as well. It varies from model to model.
     
  11. mattack

    mattack Well-Known Member

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    If you can point me to exact details about what pins to check for what voltages, that would be GREAT! (I would likely pay you a bit if it ends up in me fixing my Tivo cheaply!)
     
  12. unitron

    unitron Well-Known Member

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    I've never, to the best of my knowledge, been in the physical presence of the outside of any of the three S3 platform models, much less had a chance to explore the insides of any of them.

    If the world wide web information explosion actually included stuff like being able to get a look at an actual schematic diagram, much less a service manual, for an S2 and up TiVo, I could look at it and tell you in seconds where to check for what voltages.

    But the world doesn't work that way yet.

    As I am currently enjoying the misfortune of seeing the insides of both my S1s and both my S2s I can tell you that the S1 power supply has a 3.3V rail, a 5V rail, a 12V rail, and a 32V rail, and that the S2 dual tuner has a 5, a 12, and a 32.

    If your readings are within about 10% either way, that's probably acceptable. Besides if you adjust the variable resistor on the power supply sircuit board that you aren't supposed to be adjusting, you'll probably get one of the voltages right on the nose only to find the others are now out of tolerance.

    The 5 and the 12 are easy, you just hook your voltmeter's black lead to ground and use the red lead to check the red wire (+5V) and the yellow wire (+12v) on the hard drive Molex connector.

    For the rest of it you hope you have a skinny enough probe on the end of the red wire to get into each individual hole (without shorting to the one on either side), either on the motherboard end socket or the power supply end socket of the cable that connects the two, and see which is which.

    Of course verifying that you have all the voltages listed on the label wrapped around the biggest capacitor on the power supply (thank heavens for that scrap of info, at least) doesn't tell you if any of the components fed by those voltages is faulty or not.

    The fastest way to troubleshoot is swap in a known good power supply and see if that fixes things. If it does, you've got a bad power supply. If it doesn't, you've got a major headache.

    And right now, I've got a doozy.
     

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