MBA A1466, water damage, SMC problem?

Discussion in 'MacBook Air' started by laptopmd, Mar 5, 2014.

  1. laptopmd macrumors newbie

    May 31, 2013
    Hi there !

    I have a part-time job as laptop (most apple) and mobile phones repair.

    I have got a Macbook Air A1466, with water (but i suppose tea) damage.
    Removed all water traces, checked all components, no shorts anywhere.

    But the problem is that the mba doesn't not charge battery and does not power up.

    So i followed the line from the battery connector, back to U7201 and found that PP3V3_S5_REG is missing. Searching again and i found that i don't have the "enable" signal called P3V3S5_EN , because is missing the most important signal : SMC_PM_G2_EN

    This signal comes directly from the SMC, that it was water damaged too.

    It is possible that SMC is damaged, or i should check if there is other signals missing ? Important voltages like PPBUS_G3H (smc power voltage) are presents.

    I have ordered a new smc chip, to swap with this one, just in case...
  2. cyber16 macrumors 6502

    Jan 12, 2013
    Magsafe I/O board and its ribbon cable for the no charge, then power on comes from the uppercase keyboard that is a usb interface connected via the touchpad then to the logic-board.
    Pull the touchpad off, look at the underside board, clean both ribbon connectors. try again,
  3. laptopmd thread starter macrumors newbie

    May 31, 2013
    Thank you cyber16 but already tested that.

    I/O board is working, voltages goes to the mainboard.

    By looking at the power states, SMC_PM_G2_EN must be enabled even when the laptop is turned off (S5 state), but this signal is missing.
    What i don't know if this signal is enabled from another pin of the smc, or just turn it on when power is given to the chip.

    I think i will only know that when i replace the smc chip.. :(
  4. greekhero macrumors member

    Oct 24, 2013
    Hi laptopmd, I have the exact same condition, where the SMC_PM_G2_EN is low (0.02V). I have a working A1466 (2013) as well that shows 0V when only battery is connected and 3.42 when teh adapter is connected. The bad one neither charges nor turns on. G3H is available everywhere and the power is coming properly. Did you ever change the SMC? If so, did it work? Any ideas would be great!

  5. greekhero macrumors member

    Oct 24, 2013
    Just to see if it helps anyone. Mine did have problem with the SMC, which lucky for me, I was able to clean using a fine painters brush with IPA. Once the SMC was cleaned, the power came right up!
  6. laptopmd thread starter macrumors newbie

    May 31, 2013
    Hi greekhero,

    no i have changed the SMIC but still nothing..

    I have left this macbook on my drawer, i am repairing other toys meanwhile, i will return back to this one in future..
  7. oliv3r macrumors newbie

    Dec 7, 2014
    Just trying to fill in/add into etc etc.

    I also have a Macbook Air (2013 model) that had some tea spilled on it. It was so little, that all the 'water detection stickers' are still okay. There was some corrosion between some pins unfortunatly however.

    Anyway, I managed to clean everything out quite nicely, it's probably not even visible anymore, even if you know where to look!

    Everything also works properly again with the Macbook book, both in OSX and in Linux; except for one thing. Shutdown. If I shutdown/hibernate, the machine refuses to wake. I have to disconnect the battery, connect to the power supply connect the battery (or something close to this voodoo) to get it to power up. After that, no problem, suspend etc all works. Also if I leave the laptop in suspend too long (and thus the battery drains), connecting the PSU results in proper power up too.

    I'd almost looks like the SMC has a 'water damage protection' bit that once set, can't easily be cleared unless you have access to some apple tools?! Obviously I can't get apple to even examine this, as they'll quickly say 'cover removed; water damage NO WARRANTY' and I can't blame them, well a little I can.
  8. jimbojones23 macrumors newbie

    Mar 17, 2015

    Did you ever manage to sort this out?

    I have similar issue, also involving prolonged randomised pressing of the power key to boot it up.

    Most of the time the fan will spin with no boot or chime.

    Once booted its fine, sleeps fine and wakes fine. Passed Diagnostics without fault.

  9. oliv3r macrumors newbie

    Dec 7, 2014
    Nope, not yet.

    If, for whatever reason the machine gets turned 'off', I have to unplug the battery, disconnect power, press the powerbutton, connect power, watch the fan try to spin (and the LED change from green to orange and back) and then connect the battery. It then runs fine again for months to an end. If the battery runs down, that's not a problem either, as it then boots normally.

    I have tried booting with refit and doing an SMCFlasher -reset 1, but that always fails with an 'unknown parameter' error. I should let the battery run down and try it then, as I guess it is not in 'SMC bypass mode', which it is in the other cases.

    I should be able to take it to the apple store, say 'look, this machine runs fine whatever I throw at it, Suspend, resume, reboot, fans are quiet. Even dual booting linux and OSX no problem. Just don't try to shut it down. This is not a 'logic board error' but purely a software issue, go fix it! But ... i'm fairly certain they won't even get near it and call it the 'water damage protection circuit'.
  10. G-Logic macrumors newbie


    Aug 18, 2014

    16 volts12 volts ok even replace ISL charging IC but still same prob ie no
    5 votls stanby voltages missing.

    1no SMC_PM_G2_EN ie .4voltsv.
    2no SMC_RESET_L ie .4 volts.
    3no SMC_ADAPTER_EN ie .4volts

    BUT after Reflow 
    or appling Heat to SMC IC problem resolve.
    1no SMC_PM_G2_EN ie 3.4voltsv.
    2no SMC_RESET_L ie 3.4 volts.
    3no SMC_ADAPTER_EN ie 3.4volts.

    ALL my voltages came up.

    heheh Enjoy...

  11. cisasteelersfan macrumors newbie


    Jan 14, 2016
    I'm having the exact same problem as both olyv3r and jimbojones23: I recently purchased this computer (mid 2012 MBA, A1466) and when it was given to me it was on standby. I open the screen, and everything worked 100% perfectly. I even rebooted several times with no issue.

    Then, I shut it down. Now I can't get it to turn back on! Previous owner said that they 'just plugged it into the wall and it turned on' - I'm thinking it was totally dead (battery at 0%) and then power automatically turns it on.

    I have a few options:
    1. Wait a few months until the battery is completely drained, then plug it in, and it should start up... (however when it was working I saw that it only had 149 cycles on the battery, so it is very healthy and will probably take a long time to discharge)
    2. Take it to an Apple store (~80mi away from my house :( ), it's not under warranty, but maybe they can tell me something.
    3. I just ordered a pentalobe driver off of eBay. I can try some of the tricks above like unplugging the battery, etc. Also I might try shorting the power-on pads on the mobo.

    Thoughts? Anyone else have this problem? The 'reset SMC' thing where you hold down shift-ctrl-option-pwr does nothing. I can't get the laptop to do anything.
  12. Ian.C macrumors regular

    Mar 6, 2008
    Lancashire, UK
    Look at this video, and more Louis has put on you tube. they have certainly helped me fix a few macbooks in the past

    hope this helps


  13. mohitjain1112 macrumors newbie


    Jun 25, 2017
    Hello i have purchased an used retina late 2013 15 inch macbook from an unknown individual macbook is in extended warranty because of this i have purchased it without much checking

    but after using it for one month i feel there is an problem of noisy fan at that time mac is in warranty so i have take the macbook to nearby apple care which is 30 km away from my home

    i have submitted my macbook one day later received a call they tell me mac is liquid damaged i visited the service center he opened the macbook in front of me and showed marks of tea spills and he said warranty is void due to liquid damage

    so i take the mac back and used it normally but after some days the sound of fan become very noisy i decided to reset the smc but after resetting the smc macbook doesn't switch on and doesn't charge

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