Cleaning a logic board

Discussion in 'MacBook' started by bplein, Dec 4, 2008.

  1. bplein macrumors 6502

    bplein

    Joined:
    Jul 21, 2007
    Location:
    Austin, TX USA
    #1
    All-

    I aquired a dead MacBook that had been the victim of a coffee spill. The interesting thing is that if I disconnect the power for a week or even a few days, I can boot the system, but within minutes (or seconds) the system will "die", with no video or drive access, but still has the fans going. If I try to restart, it will not, unless I remove the battery and power for several days. The longer the duration of "no power", the longer the system stays on when I do power it up.

    So I am guessing that the coffee is shorting something, but BARELY, and over time the charge dissapates and lets the system come back online.

    Since I bought this MacBook for the spare parts (screen mainly), I'm willing to be pretty drastic and try and clean the logic board, hoping that I can clean up what appears to be a slight short.

    Does anyone have any experience with products designed specifically for cleaning circuit boards, and using them on a PC or Mac motherboard? I would like to find a spray-on solution that will drive out any crud (it's apparent that the guy used sugar in his coffee), and the ability to dry completely (not an oil like WD-40).

    I can always attempt to use rubbing alcohol, but I wouldn't mind using a commercial fluid specifically designed for cleaning circuits. I will most likely remove the entire logic board for this cleaning project.

    Any ideas?

    Thanks in advance...
     
  2. shady825 macrumors 68000

    shady825

    Joined:
    Oct 8, 2008
    Location:
    Area 51
    #2
    found this on another site dont know if it helps but here ya go:

    What do I use to clean this mess? Soap and water, believe it or not. The boards are usually easily removed, and hot water, soap and a toothbrush is just the ticket. After the bath, I lay some paper towels on a hard surface and tap the edges of the board on it to drive the water out from under the components. A few judicious shots of aerosol contact cleaner for the really stubborn water droplets and then a good session with a hair dryer and the board is good as new.

    http://www.vintage-computer.com/vcforum/archive/index.php/t-1902.html
     
  3. bplein thread starter macrumors 6502

    bplein

    Joined:
    Jul 21, 2007
    Location:
    Austin, TX USA
    #3
    Thanks, although I am avoiding the water for one primary reason: I don't know if there are any components that can capture and hold on to the water. I'd rather use a volatile fluid (yes, I know that may not be too "green") so I can be certain that after cleaning that the cleaning solution is gone on a timely basis.

    But who knows, maybe I'll try this. Thanks.
     
  4. shady825 macrumors 68000

    shady825

    Joined:
    Oct 8, 2008
    Location:
    Area 51
    #4
    no problem, just tryin to help out..
    You also might want to consider "contact cleaner", it can be found at auto part stores. Its used for cleaning out electrical contacts in trailer hitches and such where corrosion is a problem.
     
  5. JG271 macrumors 6502a

    JG271

    Joined:
    Dec 17, 2007
    Location:
    UK
    #5
    I think alcohol of some kind might be the best bet - it'll evaporate before causing any further damage and is a good cleaner too.

    Let us know how it goes, it'd be an interesting project and great if you get it working again!
     
  6. milk242 macrumors 6502a

    Joined:
    Jun 28, 2007
    #6
    I believe you should use 100% isopropyl alcohol (rubbing alcohol).
     
  7. bplein thread starter macrumors 6502

    bplein

    Joined:
    Jul 21, 2007
    Location:
    Austin, TX USA
    #7
    I bought a can of MG Chemicals "Electrosolve" which is a non-conducting cleaner spray using volatile liquids (hexanes, pentanes, blah-blah-blah-anes). I took the computer outside with the upper case (keyboard), hard drive, battery and memory removed and blasted it out thoroughly, allowing the liquid to get in and around everywhere.

    The problem with this stuff is that it's bad stuff, very flammable and dangerous to breath in closed areas. It also is compressed and evaporates easily, so it chills the area down and you get condensation. After the majority of this fluid leaked off or dissipated, I blew it out with a hair dryer on cool, then on warm, until the board was dry. Then I dried it out a bit longer, and fired it up.

    The system works GREAT now. They whole key was that the liquid damage didn't fry any components, but rather just shorted the system enough to prevent proper boot.

    Your mileage may vary, but this one cleaned up nice!

    Pretty good, another MacBook in the house for $100 plus a can of Electrosolve.
     
  8. Matty0500 macrumors newbie

    Joined:
    Oct 19, 2008
    #8
    being an electronic technician, I use deoxit all the time on circuits, it's designed to carry away dirt. It works pretty well but honestly the best thing for sugar is just water. Give it a quick bath and blow it off with compressed air . let it sit for a week to make sure it's dry and fire it up.
     
  9. bplein thread starter macrumors 6502

    bplein

    Joined:
    Jul 21, 2007
    Location:
    Austin, TX USA
    #9
    Well, the cleaning spray worked great. Of course, I destroyed a keyboard connector taking it off, but i have a spare blackbook keyboard.

    Here's the temporary result (will put a white keyboard on it this weekend). Until then, I dub it "the PandaBook"
     

    Attached Files:

  10. mynameisraj macrumors 6502

    Joined:
    Nov 14, 2008
    Location:
    Boulder, Colorado
    #10
    Wow that looks good…*You should keep the black keyboard but swap out the top case for a white one :D
     
  11. bplein thread starter macrumors 6502

    bplein

    Joined:
    Jul 21, 2007
    Location:
    Austin, TX USA
    #11
    Well, the keyboard and top case are a single unit. I could swap the keys, but this keyboard is a late model, and the white spare I have is early. That means the Function keys are different. So this one, volme is f10-F12, and if I put on the white key tops, they'd be messed up.

    I have two buyers lined up for it with a white keyboard. I'll keep the black one, and find some more broken macbooks and fix them up! (new hobby)
     
  12. shady825 macrumors 68000

    shady825

    Joined:
    Oct 8, 2008
    Location:
    Area 51
    #12
    Good job! Im glad you got it working!!
     
  13. uurxin macrumors newbie

    Joined:
    May 16, 2011
    #13
    question

    sorry to bring this thread back to life...but i had a question

    when washing a logic board should you remove the heat sink..or is the water (~140deg) not hot enough to affect the thermal paste?
     

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