mbp power supply "accident"

Discussion in 'MacBook Pro' started by deadnid, Apr 26, 2011.

  1. deadnid macrumors newbie

    Joined:
    Apr 26, 2011
    #1
    Hello to everyone, I'm new to this forum. This is a question for the technical experienced.

    I have a 2008 macbook pro 15". After 3 years of every day use, the cable of the power adapter got worn at the point were it comes out of the plastic and I caught it making spikes (shortcircuiting). So I break opened the adapter, cut the cable at the defective point and renewed the soldering etc. Everything would be just fine, but... it seems I was so tired and absent minded that (as it turned out later) I soldered it in reversed polarity... I then tried on my laptop and nothing happened, no power, not even adapter LED glowing.

    Long story short, now the power input of the laptop doesn't work (tried with other adapter as well). With a charged battery it's fine. Obviously something inside there, at the power input section is fried. Question is, do you know if there is some protective fuse/resistor or something like that, that can be replaced or there is only SMD that can't really be repaired? Any info appreciated.
     
  2. mac8867 macrumors 6502

    Joined:
    Apr 5, 2010
    Location:
    Saint Augustine, FL
    #2
    Electronic design 101 says there was a large "gate resistor" protecting the inner circuitry (I say "was" because you fried it when you reversed the position of ground). How that gets replaced, I am not sure. Take it to an Apple store.
     
  3. deadnid thread starter macrumors newbie

    Joined:
    Apr 26, 2011
    #3
    Obviously that's what I should do, I just fear the possibly overrated cost of this repair, even when it's only a simple resistor replacement. Of course I hope it is just that! thanks for the info!
     
  4. wywern209 macrumors 65832

    wywern209

    Joined:
    Sep 7, 2008
    Location:
    do you rly want to know?
    #4
    i think it was bad foresight on your part to try and repair the adapter. you would have been better off just taking it down to the apple store. they might have even discounted you for the price of a new one. if it still had applecare, they would have given you a new one for free. I think they might have to replace the whole logic board so your sorta SOL cuz i think that is 1k.
     
  5. deadnid thread starter macrumors newbie

    Joined:
    Apr 26, 2011
    #5
    Yes that's exactly what I fear. We'll see, I'll let you know how this goes. Concerning the attempt to repair the adapter on my own, I've repaired tons of adapters of various types in the past as well as other more complex electronic devices. I'm not a pro electronics guy but I'm not a newbie as well. It was just a very bad moment for my brain... it's so tragic when you come to think that it's just 2 wires... a blue and a brown... I confused just 2 colors... My mind made me believe that the brown was originally the ground and I was so sure that I didn't measure with a multimeter. In the end, it was the blue... but too late. So so silly... It's what people say "never do repairs etc. when you feel tired, just leave it for the next day"...
     
  6. TheIguana macrumors 6502a

    TheIguana

    Joined:
    Sep 26, 2004
    Location:
    Canada
    #6
    I am not entirely sure whether the gate resistor is on the DC-In board or the Logic Board. If it is the DC-In board you can get a replacement from iFixit for about $50. If it is on the logic board I guess you can try and track down the fried component with a multimeter and then desolder the bad component and put a new one on there but that will be quite the repair. Otherwise a new logic board will be rather pricey.
     
  7. goMac macrumors 603

    Joined:
    Apr 15, 2004
    #7
    I would be willing to bet it's on the DC board. But no way of knowing until you go to the Apple Store. But Apple generally compartmentalizes anything that could be taken out by a bad power adaptor.
     
  8. deadnid thread starter macrumors newbie

    Joined:
    Apr 26, 2011
    #8
    Thanks! I did a google image search on the DC-in board and it looks like there are some components on it. So now I can only hope that this is the only thing dead. Do you think that if it so, still the official service would suggest a logic board replacement? :(
     
  9. deadnid thread starter macrumors newbie

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    Apr 26, 2011
    #9
    Actually I just noticed that the spare DC-in Board on ifixit.com is for the Unibody 15"... Is it the same for the old design? (Mine is NOT the Unibody)
     
  10. TheIguana macrumors 6502a

    TheIguana

    Joined:
    Sep 26, 2004
    Location:
    Canada
    #10
    My bad I went with the assumption that you had a late 2008 unibody not the early 2008 model (model A1260). Just to be certain we have the right model in mind run through the ID Your Mac guide on iFixit's site.

    If your MBP's model is indeed the A1260 then the magsafe port is on what is called the Left I/O Board.
     
  11. deadnid thread starter macrumors newbie

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    Apr 26, 2011
    #11
    thanks Iguana. It's the A1260. I think I'm going to try and replace this $100 board on my own... oh well, some people never learn! :)

    I see different part numbers for the board on various online stores, for instance 922-8356, 076-1318, 922-7911, 922-7187. Do you know if there is any practical difference between them?
     
  12. TheIguana macrumors 6502a

    TheIguana

    Joined:
    Sep 26, 2004
    Location:
    Canada
    #12
    922-8356, 076-1318 are the specific part numbers that Apple assigns to your model MBP (A1260). 922-7911 is for the A1211 and 922-7187 is for the A1150. The boards look fairly similar but I think your best bet would be to stick with either the 922-8356 or 076-1318 just to make sure you don't have any problems with compatibility (ie connectors).

    One last note if you didn't see it already iFixit has a guide for taking apart your MBP and installing the replacement IO card. Could be helpful once you get your MBP opened up.

    Good luck with the repair and let us know how it turns out!
     
  13. FOX160 macrumors regular

    Joined:
    Mar 2, 2011
    #13
    I know what you need to do is have a firm wire update.

    Same thing happened to my Daughters Mac Book one Apple store
    said it was the battery so £ 100 sterling pounds for a new battery.

    Then still failed to work went to another Apple store and they
    noticed I had an up to date power cable and then the Genius
    done a firm wire up date and all is fine now and did not need a
    new battery.

    Apparently this happens a lot where people buy a newer version
    of the power adaptor and do not up date the firm wire.

    I did say it would help if that info was in big print on or in the box.
     
  14. noire anqa macrumors regular

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    Aug 20, 2010
    #14
    I love this post.
     
  15. noire anqa, Apr 27, 2011
    Last edited: Apr 27, 2011

    noire anqa macrumors regular

    Joined:
    Aug 20, 2010
    #15
    I think you should be fine with replacing the DC board, i used to fry it all the time on the old PowerBooks, went through at least 5 of them. The jack-type, ring power adaptors used to short circuit really easily and fry whatever they were connected to. Never once lost a logic board as a result though, the DC boards always bore the brunt of it.

    I'd be surprised if it were any different for MBPs.

    Good luck!
     
  16. deadnid thread starter macrumors newbie

    Joined:
    Apr 26, 2011
    #16
    As I've already said it was my bad, mistakenly inverting the polarity of my adapter which then fried the DC-In board. Now, in simple terms, there is no path for electrical power to get into the machine. I can't see what this has to do with any firmware update. thanks anyway
     
  17. devilstrider macrumors 6502a

    Joined:
    May 12, 2010
    #17
    Man just take the thing to the Apple Store and see what they say. You already screwed up once because you are to cheap. Now take it to them before you cause more damage. If you can't afford to fix it don't buy it.
     
  18. deadnid thread starter macrumors newbie

    Joined:
    Apr 26, 2011
    #18
    am about to order the part now. Thanks to everyone, you've given me hope! and a chance to get to know my trusty macbook from the inside...

    oh and of course I'll let you know how it goes
     
  19. alphaod macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    NYC
    #19
    Take it to the store and admit to nothing that would implicate you.

    If you're curious, this is what the Apple Store Geniuses told me; if I say anything about doing my own repair, it's immediately my fault, but if I don't mention it, I have no liability.

    Of course this means there aren't signs of physical damage like prying, etc.
     
  20. Al Coholic macrumors 6502

    Joined:
    Mar 10, 2011
    Location:
    Under the I-470 Freeway
    #20
    Holy crap. Listen to some of you guys. Just take it to a freaking Apple rep. Why is this such a difficult concept to fathom? Exercise your electronics prowess on your own dime.

    +1

    Wow. Here's a novel idea.

    Oops. Too late! Wear goggles and make sure your homeowner's insurance is up to date! :D
     
  21. walterwhite macrumors 6502

    walterwhite

    Joined:
    Jan 22, 2011
    Location:
    South Central PA
    #21
    As a past Genius... they arent going to know what happened unless "A" you tell them or "B" you show them the adapter you tore apart... just take in the computer to the Genius Bar and say it doesnt work... Even if they see something burnt inside, they assume positive intent and will probably fix it for you. You have nothing to lose by finding out.

    It sounds like the magsafe board - very cheap and they can try swapping that very quickly to see if it fixes it.
     
  22. noire anqa macrumors regular

    Joined:
    Aug 20, 2010
    #22
    Well, you're right .. sort of.
    I agree - take it to a genius, if you have apple care.

    Otherwise the OP is spot on in his attitude..
     
  23. Al Coholic macrumors 6502

    Joined:
    Mar 10, 2011
    Location:
    Under the I-470 Freeway
    #23
    "sort of" right?

    If you take it in they'll diagnose it for you. Applecare or not. Free. None of this silly-assed guesswork going on here.

    You guys crack me up. :D
     
  24. deadnid thread starter macrumors newbie

    Joined:
    Apr 26, 2011
    #24
    free diagnose? didn't know that. Haven't taken any step yet, be it apple store or diy, just super busy days. No I never had Apple Care.

    I appreciate all of your thoughts and opinions. I'm in favor of the diy approach just because I'm used in fixing my (and not only) things on my own since like forever. It's just a habit. If it's good or bad I don't know but it has helped me tremendously in my life and job (sound tech/engineer). Of course one must always know his limits. A diagnose isn't within mine but the replacement of the DC-in board with the help of the online guide is. And it will be adventure! If it turns out as an epic failure, then well ok... I'll never let you know! mouhaha
     
  25. deadnid thread starter macrumors newbie

    Joined:
    Apr 26, 2011
    #25
    success!

    Ordered and replaced the "Left I/O board" today. MBP looks like new!

    The first time I closed up the case, the machine wouldn't power up, though the battery was charging fine. After about an hour of super frustration I discovered that if I pushed the ribbon cable of the trackpad/keyboard with my finger over it's connector on the logic board, then it would power up... It was just a loose connection so the button wouldn't respond to the board! A great relief! I then sticked a thin piece of rubber on top of the connector so that it always gets pushed downwards towards the logic board and it works fine since. How silly!

    Also got a chance to dust off the internal, which wasn't that bad for a 3 year old machine... and I've been using it heavily on various places.

    Before I closed the case for good, I was working for about an hour on internet stuff when I got a kernel panic (grey screen) for the first time in my life... But I guess it had to do with the case (including the RAM area...) being loose. So I hope... Will let you know if new problems come up. cheers
     

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