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Help I need a cap valve

Discussion in 'TiVo Series3 HDTV DVRs' started by timhbtr53, May 21, 2014.

  1. timhbtr53

    timhbtr53 Grumpy Old Man

    307
    1
    Apr 24, 2014
    In the Deep...
    For C578 on the main PCB. I had one shipped to me and the drive cage was not screwed down and it knocked off the cap at C578. The model number is a TCD648250B If anyone could help me please. The cap is right behind the turner board the one toward the back going across the unit in the front. It is almost center of the board. All I have is one leg sticking up. Thanks for any help.
     
  2. squint

    squint New Member

    846
    0
    Jun 15, 2008
  3. unitron

    unitron Active Member

    16,387
    2
    Apr 28, 2006
    semi-coastal NC
    Where are you and do you have any experience de-soldering and soldering Surface Mount Devices, especially under circumstances requiring a magnifying glass?


    Valve (from "thermionic valve") is what they call a vacuum tube in the UK.
     
  4. timhbtr53

    timhbtr53 Grumpy Old Man

    307
    1
    Apr 24, 2014
    In the Deep...
    Thanks squint that's what I need. And unitron yes I do have done Surface Mount a few times. I have access to a weller hot air station. But the way the cap was broke off I can get it with my very small "princess weller solder pin". Now I have to remember how to read the cap for "pf" and voltage. Need more coffee just started on cup one. Thanks Guys.
     
  5. unitron

    unitron Active Member

    16,387
    2
    Apr 28, 2006
    semi-coastal NC
    I'm pretty sure I remember the 16Z part being the working voltage.

    As it happens I had a similar incident with an S2 DT when installing a dual drive bracket.

    I bought a non working 648 board off a member here to cannibilize for a cap, but even though I had the remains of the damaged one to read the top of, the transplant was a failure and I wound up getting another 649 board and transplanting the crypto chip from the broken board in order to be able to access about 1TB of shows.

    (worst comes to worst, you can do the same with your 648 board and another good one to save the lifetime sub by moving the TSN)

    I told you that story to tell you this one.

    I managed to find C578 on my junk 648 board, and it's just like the one in squint's picture, except it says 621 where his says 623.

    According to this diagram I stole from a website that stole it from the Mouser catalog, those are lot numbers (so I guess his caps are 2 weeks newer than mine but both from '96), the middle figure is capacitance in some unit*, and the bottom is WV.

    [media]http://www.repeater-builder.com/motorola/spectra/spectra-caps/cap_dim.jpg[/media]

    (click to enlarge)

    *It doesn't, for repair purposes, matter what the value is as long as it's the same as the one it's replacing.
     
  6. timhbtr53

    timhbtr53 Grumpy Old Man

    307
    1
    Apr 24, 2014
    In the Deep...
    Thanks unitron. The problem I'm having is I have no signal from cable or OTA ant. Both or working coax. And the modulator board is getting hot real hot so I think that cap is a filter cap to the mod boards. I do have a non life time s3 I can steal a cap from so I will give that shot in the morning. It's too hot in Louisiana to do anything else but stay in with the A/Con. Thanks for the info. Tim in Baton Rouge...
     
  7. unitron

    unitron Active Member

    16,387
    2
    Apr 28, 2006
    semi-coastal NC
    If the problem lifetimed unit and the other one are both 648250s, I'd advise not cannibalizing the other one but saving it for a possible crypto chip transplant from the lifetimed one.

    The TiVo Service Number, to which the lifetime sub is tied, is contained in the crypto chip, and if you move it to the other 648 board, you move the TSN and it never knows it's not where it always was.

    If you aim the back of the motherboard at your stomach, then the antenna and cable inputs are in the near right corner.

    To the left of it are the 2 cable card slots with the eSATA port in between.

    Go straight to the front of the unit from the eSATA port, and at the end of the cable card slots there's a quad flat pack that says Atmel on it and another quad flat pack just beyond that with a paper label on it.

    The one with the label is the PROM and doesn't need to be moved if you aren't using a hacked PROM, and the one that says Atmel is the crypto chip.

    You could swap crypto chips between the units, giving you a working lifetimed unit immediately, and then troubleshoot the other one at your leisure.

    Would you want to pay postage on a parts board?
     
  8. timhbtr53

    timhbtr53 Grumpy Old Man

    307
    1
    Apr 24, 2014
    In the Deep...
    I have the TCD648250B and I see the chips you're talking about. Yes if you have a board PM me later when you get a min and I can paypal you some $ for S&H. Man that would be great I do have a non LF TCD652160 that works that I got for free but that's not going to help me.
     
  9. unitron

    unitron Active Member

    16,387
    2
    Apr 28, 2006
    semi-coastal NC
    So you only have the one 648?

    I'll admit I'd rather send you the whole board than try to successfully unsolder that one SMD cap and send just that to you.
     
  10. squint

    squint New Member

    846
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    Jun 15, 2008
    The 652 appears to have 4 of those capacitors beneath where the hard drive is mounted.
     
  11. timhbtr53

    timhbtr53 Grumpy Old Man

    307
    1
    Apr 24, 2014
    In the Deep...
    Unitron I just got on and if you will PM me a phone number I can call you and set up something with you. I do have access to hot air SMT station any time I need it and mine should be back from a friend I let use a few weeks back. Thanks Tim....
     
  12. unitron

    unitron Active Member

    16,387
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    Apr 28, 2006
    semi-coastal NC
    I won't be up to thinking about the logistics of mailing a package until sometime after the weekend. Apparently a tooth extraction can trigger flu-like symptoms.

    But if you're confident in your abilities, and not using that 652 at the moment, you could always use one of the same value caps out of it to fix the 648 (or see if that's going to be all that it takes to fix it), and then replace it in the 652 with my cap later on.
     
  13. squint

    squint New Member

    846
    0
    Jun 15, 2008
    If there were no other TiVos to cannibalize, would it be possible to buy a replacement capacitor?
     
  14. timhbtr53

    timhbtr53 Grumpy Old Man

    307
    1
    Apr 24, 2014
    In the Deep...
    Yes I can order one from mouser. I have one I lifted from a old board but yes a new one would be the route to take. I am going to order a couple and replace the one I lifted. Unitron hope you fell better I know how those tooth "lifted" can do some strange things to you. Hang in there and take care.
     
  15. unitron

    unitron Active Member

    16,387
    2
    Apr 28, 2006
    semi-coastal NC
    The extraction process itself (tugging and twisting) seems to have immediately triggered a severe sinus headache that didn't subside enough to let me sleep until 24 hours later, but I think I co-incidentally picked up a respiratory system virus that started in on me shortly after that.

    One of those things that wants to be the flu when it grows up but fortunately isn't as bad as the real thing.

    Thanks for your good wishes, and let me know if you still need parts.
     
  16. timhbtr53

    timhbtr53 Grumpy Old Man

    307
    1
    Apr 24, 2014
    In the Deep...
    Oh man that does not sound like much fun. Well I found a cap "I keep forgetting about local friends" I floated it in and like I guessed it made no change on the tuner. It looks like I am going to have to find a board and lift some chips. You sir have been a wealth of info and I do thank you. If you know of a board please let me know. Thanks and I pray you fell better real soon.
     
  17. unitron

    unitron Active Member

    16,387
    2
    Apr 28, 2006
    semi-coastal NC
    Okay, now you're into "the easiest thing to do is find an unsubbed working board and move the crypto chip over" territory, because if replacing the part you knocked loose doesn't get it running again, then heaven only knows what's really wrong or what needs replacing.
     

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