Backlight out - help needed

Discussion in 'MacBook' started by eoren1, Jul 7, 2009.

  1. eoren1 macrumors 6502

    Joined:
    Aug 17, 2007
    #1
    I'm using a 2007 Macbook (2.2Ghz core 2 duo) and had been having intermittent problems with the backlight going out. At first, it happened a few times a week and moving the lid down and back up would usually work to get the backlight turned back on. In the past week, it became more frequent - multiple times a day. Finally decided that it was worth trying to work on. An internet search left me with two possibilities: the inverter or the backlight itself. Figured since this seemed to be fixed with moving the lid, that maybe the wires to the inverter were loose. So I removed the bezel and then the plastic hinge cover. Saw that the inverter was in place without anything clearly loose. Closed the cover (which took some work:() and then put the bezel back on. Well, I definitely didn't help matters as the backlight is harder to get back 'on' now. I can still get it to turn on but usually with extending the lid all the way open, closing it almost all the way, then opening it back up. I only went down this road as I do not have Apple Care. Was hoping someone could offer suggestions on what to do next.
    Thanks in advance,
    E
     
  2. l.a.rossmann macrumors 65816

    l.a.rossmann

    Joined:
    May 15, 2009
    Location:
    Brooklyn
    #2
    I can't say I know what's wrong without seeing it. Common problems, listed in order of how often it occurs to me on a day to day basis:

    a) The hinge cover is hard, and is a very tight fit with the inverter. It can, when you put it back on, knock things on the inverter, causing intermittency issues. Fixed with a new inverter, or finding loose parts and soldering them back on properly. Properly = no radioshack iron, or thick tipped iron. A hakko 936 with a micro tip does quite well.

    b) The cable between the inverter and the LCD is crimped somewhere. Solved by cutting it at the end, putting a new one on. Use wire cutters, wire splicers, 91% alcohol, and heatshrink. Clean the tips where wire is exposed. Wrap to a new inverter board wire(I have about 150000 of them here) twisting one rotation at a time, not senselessly like a twist tie. Wrap it around itself, then slide the heatshrink over. Make sure when you put this back, that this wire rests under the LCD, not behind it.

    c) The wire from the inverter board to the logic board is F'd somewhere. I have never had this happen, but it is a possibility.

    Good luck.
     
  3. eoren1 thread starter macrumors 6502

    Joined:
    Aug 17, 2007
    #3
    Thanks Louis!
    I think I'm going to start by ordering a new inverter board ($10 off ebay). I am working on the macbook now with the bezel and hinge cover off. If this replacement works, I'm inclined to cut off the protruding ends of the hinge cover to keep it from potentially pinching any wires.
    As an aside, I was easily able to access the inverter by taking the bezel and hinge cover off. I'm assuming this is the best method to replace the inverter (and not ifixit's 23-step process that takes the whole macbook apart). Would you suggest that I trace the wires leading to the inverter back up to the lcd and down to the logic board by doing a more thorough take-apart while waiting on the part?
    Thanks again,
    E
     
  4. l.a.rossmann macrumors 65816

    l.a.rossmann

    Joined:
    May 15, 2009
    Location:
    Brooklyn
    #4
    Poke things while it's on with a non electrically conductive object. Shake certain parts. See what's moving when you open and close it. This is how you find intermittent parts.

    I like a pencil eraser, because a pencil is always around.
     
  5. eoren1 thread starter macrumors 6502

    Joined:
    Aug 17, 2007
    #5
    Update

    So the backlight went out completely and I ordered a new inverter board ($17 shipped off eBay). Got it today and replaced the old one with immediate success - the backlight was back! However, I continue to have outages of the backlight with moving the screen. Also seemed to have outages as I put the bezel back on and pressed on the bottom of the screen to put it in place. I have a feeling that one of the wires is shorting out and am wondering where that wire might lie. Would you recommend removing the lcd or going in through the body? Are any of these wires replaceable (short of splicing in new cable)?
    Thanks again,
    E
     
  6. eoren1 thread starter macrumors 6502

    Joined:
    Aug 17, 2007
    #6
    A solution!

    I ended up walking into an Apple store and talking to a genius about the problem. He quickly traced it to what was likely a shotty inverter cable leading to the logic board. I ordered the part off eBay and took apart the Macbook. Unfortunately, once the Macbook was apart, I realized the new cable didn't fit the board! I reseated the original cable and put the Macbook back together and..........all is well!!! So the original cable was basically just reseated and that fixed the issue. Hopefully others with similar backlight issues will see this and note a probable fix.
    E
     
  7. MarkCooz macrumors 6502a

    Joined:
    Jul 12, 2009
    Location:
    California
    #7
    I have a friend over at apple, he's one of the tech service so he gives me some details about problems I had. well this thing happened to me before, the backlight suddenly shuts off, and etc...

    What he told me

    it could be the inverter, or the actual backlight...

    THE wire he told me rarely gets f'd up it's about 10% chance that'll be happening which in case is nothing to worry about...

    what you didn't do when you checked the inverter, you didn't check out both sides *up and down* sometimes, the inverter melts and that's what sometimes gets everything messed up

    So check out the inverter take it out, inspect it, if there's something looking weird then, you should definitely go buy a new inverter i got a brand new one off of ebay and i paid only $18 with shipping and everything

    so it's a good done deal.

    hope your problems are solved
     

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