New Mac guy intro/problem with MBA 1466 not your "usual" issue WITH VIDEO

Discussion in 'MacBook Air' started by 1gcrazy, Mar 22, 2014.

  1. 1gcrazy macrumors newbie

    Joined:
    Aug 23, 2010
    #1
    Hey guys,
    I'd like to introduce myself. I'm Steve, I've been doing laptop(mainly)/desktop repair as a side hobby since the Pentium 3. Now I focus mainly on flipping cars. I have always loved my iPhone's and have wanted a mac but it didn't happen until this week. Always been a PC guy. A guy at work had two dead macbooks: a mid 2009 MBP 13" and a 2013 MBA 13", which I ended up buying for a great price. Both "broken". I got the 2009 MBP working, which is what i'm on now, but I'm having trouble with this MBA.

    Basically, the guy had it for a week or two and spilled water on the keyboard. It drowned and it shut down. Took it to mac and with a giant bill, he decided he doesn't need a computer that bad. It's been a few months, it's had a chance to dry out but the backlight decides to work at random intervals. I'm puzzled at what is causing the problem. I have diagnosed issues with computers before, I'm not a genius by any means but I understand the real idea behind what causes what.

    The backlight comes and goes as it pleases and there isn't anything I can really do to keep it alive other than when it does illuminate it will stay illuminated for 5-15 seconds if I keep pressing the sound up/down buttons, if not it generally dies quickly. Other keys don't work as well.

    I'm thinking the keyboard might be shorting out and causing the dim button to constantly stay on(unlikely) or the inverter might be bad but how that got covered with water is beyond me.
    I ALSO want to note, I've taken this computer apart and cleaned it with alcohol and it didn't make much of a difference though, I did see a few chips with corrosion but no other obvious trouble.

    Here's a video: View My Video

    Thoughts?
     
  2. Macman45 macrumors demi-god

    Macman45

    Joined:
    Jul 29, 2011
    Location:
    Somewhere Back In The Long Ago
    #2
    A few chips with corrosion?

    My guess would be that the LB is partially fried...those chips are probably the clue.
     
  3. cyber16, Mar 23, 2014
    Last edited: Mar 23, 2014

    cyber16 macrumors 6502

    Joined:
    Jan 12, 2013
    #3
    What happens if you unplug the battery and place the back cover back on and power only with the magsafe charger?
    To eliminate both the keyboard and touchpad as being a power draw problem is simply disconnecting the one narrow ribbon cable that attaches to the logicboard from the touchpad.
    I doubt that is the problem. Could be a resistor on the backlight inverter pulsing circuit.
    Can you turn the backlight brightness down to minimize its power draw to see if that adds further on time?
    If the mba display brightness keys fail to work, just disconnected that one ribbon cable and use a usb mac keyboard that has them keys or bluetooth keyboard. The goal is simply trying to minimize the power draw to the backlight circuit to see if it helps
     
  4. 1gcrazy thread starter macrumors newbie

    Joined:
    Aug 23, 2010
    #4
    I actually don't have a charger for it yet. My charger is older and not the slimmer version. Looking at picking one up shortly though.
    Do these have replaceable backlight inverters?
     
  5. Richdmoore macrumors 65816

    Richdmoore

    Joined:
    Jul 24, 2007
    Location:
    Troutdale, OR
    #5
    I think you can get a magsafe to magsafe 2 adapter cheaper than a new power supply. If you get the macbook air working, then you can get a magsafe 2 power adapter if needed.
     
  6. 1gcrazy, Apr 16, 2014
    Last edited: Apr 16, 2014

    1gcrazy thread starter macrumors newbie

    Joined:
    Aug 23, 2010
    #6
    I just got a charger today but it's still having the same issues....

    I've actually got a few more symptoms i'll post a video shortly.
     
  7. 1gcrazy thread starter macrumors newbie

    Joined:
    Aug 23, 2010
    #8
    I don't think it's the keyboard... :(

    I unplugged the battery and connected it directly to magsafe power. I turned it on and as soon as I saw it responded I immediately unplugged the keyboard and the screen wouldn't stay lit for the full startup of the white screen with the apple logo and such.

    I did however turn it on once and it stayed on so long as I kept the volume up button pressed. I was able to use the thing like normal...with only one hand.... I went into settings to see if I could turn off the keyboard for some dumb reason(I was thinking about a previous diagnostic I had read). As soon as I disabled the multiple click keyboard setting, meaning if I hold the button it will continue to click, it went out as if I weren't holding the button at all.

    It's very particular about when it wants to stay lit up and not. Such a strange issue.

    I've also noticed that if it decides it doesn't want to illuminate at least once after the initial apple logo that if I continue to press the volume up button the screen goes nuts except with the backlight off. It'll go half screen, black, completely off(not just black[without backlight]but screen off completely) then back to home screen. All while the backlight is still out and NOT illuminated. Only stops once I let go. Keyboard light also freaks out at random times while pressing random buttons.
     
  8. 1gcrazy thread starter macrumors newbie

    Joined:
    Aug 23, 2010
    #9
    So I got the thing to stay on for quite a while tonight. I was able to literally USE it. All I had to do was time it right and keep my phone propped up on the volume up button. Crazy. Soon as I took it off it went out again.
     
  9. cyber16 macrumors 6502

    Joined:
    Jan 12, 2013
    #10
    By chance did you replace the touchpad?
    The under side of this touchpad has the usb keyboard controller and the usb touchpad controller.
    What happens if you disconnect the ONE narrow cable that goes from the touchpad to the logicboard. That will 100% remove those from the system. Yet to turn it on, you will need to disconnect the battery and plug in the charger.
     
  10. 1gcrazy thread starter macrumors newbie

    Joined:
    Aug 23, 2010
    #11
    I did not replace the touchpad. I tried starting it without the keyboard, touchpad and battery. I disconnected the ribbon at the motherboard.
    It started fine and then after the loading logo under the Apple started moving the screen got REALLY bright white, I think this is normal during startup. Anyway, it ended up going black quickly after that. Maybe a second after...
     

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