Tivo Series 3 - Bad capacitors in power supply

Discussion in 'TiVo Help Center' started by johnsom, Jul 25, 2011.

  1. Sep 9, 2015 #441 of 622
    timhbtr53

    timhbtr53 Grumpy Old Man

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    I sent you a work around that should be very easy for you.
    Let me know if you need any help.

    Tim
     
  2. BillL

    BillL Member

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    Oct 6, 2004
    Do you think that its smart or necessary to invest in a temperature controlled soldering iron for this job? Or is that overkill? I have never soldered anything in my life. Looks like you can buy a Temp Adjusting Iron by Hakko for about $90.
     
  3. videobruce

    videobruce OTA is still alive

    510
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    Nov 30, 2012
    Buffalo NY
    Handy piece of equipment. Don't skimp on cost, but no need to spend hundreds either. Easiest way is to look up models on Amazon and red the reviews. Be sure you get extra tips of various sizes & types. Also, don' forget solder wick and a solder sucker to remove the existing solder.

    Make a number of practice soldering tests, first with two pieces of wire, then if you can find a old circuit board that is bad, experiment with that. ;)
     
  4. Hank

    Hank AC•FTW TCF Club

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    I used the same Radio Shack soldering iron I've had since I was a teenager. Worked fine.
     
    Last edited: Sep 29, 2015
  5. Teeps

    Teeps Well-Known Member

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    Torrance,Cal...

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    I used a, single speed, 25W Weller soldering pencil (think I paid less than $20) for cap replacement. Works just fine; but, the tip must be clean and tinned, the work must be clean.

    Good advice posted about practice, practice, practice...
    There are some good youtube videos on PCB component replacement, too.
     
  6. HerronScott

    HerronScott Well-Known Member

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    You might look at the Weller WLC100 soldering station. Its 40W and only $38.85 from Amazon or Walmart online.

    Scott
     
  7. unitron

    unitron Well-Known Member

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    That's more and fancier than you need for a TiVo power supply.

    I don't recommend a lot of their stuff (especially the version of solder wick they changed to a few years ago), but Radio Shack has a de-soldering iron that looks like a soldering iron (pencil style, not gun style) with a turkey baster attached--it's a rubber squeeze bulb:you squeeze it and hold it that way and then use the tip to melt the old solder and then release the bulb to suck it away. You can use it to apply heat to the work to melt new solder when soldering in the new caps on something simple like the TiVo power supply board.

    Get some rosin core solder to use with it made out of just lead and tin, a 63/37 or 60/40 ratio. Anything with anything else, like silver, will drive you nuts trying to get it to melt.

    You can use the iron to melt some new solder into the old solder to get the old stuff to melt.

    There, I just saved you at least $60.
     
  8. timhbtr53

    timhbtr53 Grumpy Old Man

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    Here is a simple 60w pin great for using around the house.

    http://www.amazon.com/Meter®-Watts-...im_469_76?ie=UTF8&refRID=00Z9G7NSKCJD5VPJP3JM

    Here is a real good solder sucker ___________________________________

    http://www.amazon.com/dp/B00U1U4TTW?psc=1

    _____________________________________________________________

    And here is a small soldering station that I use when it's hot in my shack. It's a real nice Variable Power 60 Watt Soldering Station with Removable Tip plus is ESD Safe. The tips are real cheap but last a long time.

    http://www.amazon.com/gp/product/B00MCVCHJM?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

    _____________________________________________________________

    Hope this helps...
     
  9. videobruce

    videobruce OTA is still alive

    510
    18
    Nov 30, 2012
    Buffalo NY
    I would stay away from soldering "pencils". They have no temperature control. Temperatures can reach 900 plus degrees when sitting, then cool down possibly below 500 degrees when doing heavier work.
    They are always 'on', there is no cycling on/off. :thumbsdown:
     
  10. unitron

    unitron Well-Known Member

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    But the TiVo power supply is a simple single layer board, and replacing the caps is a simple soldering job.

    Now if you're replacing the caps clustered around the CPU socket on a PC motherboard or moving SMD devices, that would be a different story.

    I do recommend a minimum of 40 Watts for whatever you use on the TiVo PS, since you've got a big ground plane to fight.
     
  11. Oct 9, 2015 #451 of 622
    hunts

    hunts Member

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    Oct 4, 2006
    Illinois
    Looks like my original Series 3 Tivo power supply is bad. Is it possible to use a power supply from the Tivo HD (TCD652160) in the series 3 Tivo (TCD648250) to confirm this assumption?
     
  12. timhbtr53

    timhbtr53 Grumpy Old Man

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    Yes you can use the supply from a TCD652160 in a TCD648250B but DO NOT use the TCD648250B in a TCD652160 it has a gray line with is 7vdc and it will toast the mother board.
     
  13. HerronScott

    HerronScott Well-Known Member

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    You won't have power for the OLED display correct (assuming he wants to keep that feature)? :)

    Scott
     
  14. unitron

    unitron Well-Known Member

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    The 648 supply has an extra 7.5V section not used in the 652/658 supplies.

    Otherwise the pin-out to the motherboard is the same.

    So using a 652/658 supply in a 648 won't blow anything up or start a fire but I can't promise that for the other way around.

    However, I tried a 652 supply in a 648 a while back, expecting it to work except for the OLED display and it did not, so it might not be as simple as "the 7.5V section is for the OLED display and only that".

    The better way to test is with a Voltmeter set on the 20 or 25V DC scale.

    Clip the black (negative) lead to the metal chassis (the case) on the side away from the power supply, or jam the tip in one of the holes on that side, and use the positive (red) lead to backprobe the plug that goes in the socket on the motherboard.

    Yellow=12VDC, red=5V, orange=3.3V and gray=7.5V.

    You won't get exactly those numbers, maybe 11.8 or 12.2 or 4.9 or 5.1, although generally the 3.3 will be almost exact.

    But if it's more like 11.1 or 4.2, then that probably indicates failure.

    Also, it you get very much variation in readings depending on whether the hard drive is connected or not, that indicates an inability for the supply to "voltage regulate", which is also a sign of failure.

    It's a 648 supply. If the caps haven't failed yet, it's just a matter of time. Replace them and be done with it. Might as well do the 652 supply while you're at it as well.
     
  15. hunts

    hunts Member

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    Oct 4, 2006
    Illinois
    Alright, I'm really confused why my 40W soldering iron cant melt this connection.

    [​IMG] I can't remove the existing capacitors to replace with the new ones!
     
  16. HerronScott

    HerronScott Well-Known Member

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    Tin your soldering iron tip with a little new solder while trying to melt the existing solder.

    Scott
     
  17. hunts

    hunts Member

    84
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    Oct 4, 2006
    Illinois
    Just tried that and it still doesn't melt what is on the circuit board. :confused: I'm not a soldering pro but this isn't my first time using one either... I don't get it.
     
  18. timhbtr53

    timhbtr53 Grumpy Old Man

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    The solder on the board is a low lead solder. If you use some good solder it will help remove the old junk solder. Give that a shot.
     
  19. Hank

    Hank AC•FTW TCF Club

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    It may sound obvious but make sure your heating element is screwed in firmly. A loose element could affect heating and peak temp.
     
  20. timhbtr53

    timhbtr53 Grumpy Old Man

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    If so you have heat but yes check the tip to see if it's tight. If you can turn it with you fingers you need to use something to get it nice and tight. 40w should easily melt that junk solder I used a 28w pin once it took a long time but it worked. Are you using a solder sucker? If yes try to move the cap with heat on one leg it could be a clogged solder sucker.
     

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