A1278 Liquid damage, sound and mic issues

Discussion in 'MacBook Pro' started by viper8804, Nov 11, 2012.

  1. viper8804 macrumors newbie

    Nov 11, 2012
    Hi All,

    I have a problem with my macbook and was wondering if anybody out there can shed some light on my situation.

    I have a Macbook pro 13" A1278 mid 2010 2.66ghz. I stupidly spilt a cup of tea over it about 2 weeks ago.

    I immediately powered it off and took it apart to allow it to dry out. after a few days I put it back together and all was fine however the keyboard was faulty and the shift key was permanently on thus causing it to boot into safe mode all the time. I took the macbook apart again and found that the keyboard had burn marks as if something shorted. I purchased another keyboard off the internet and refitted everything and i could now use the macbook however the speaker with the sub attached and the mic do not work. the other speaker on the underside of the logic board does work so I have a tinny sounding mac at the moment.

    I suspected the speaker and sub combo may have been damaged whilst removing components so ordered a replacement however fitting it today there i is no change. I am starting to suspect there is a logic board fault so I used a multimeter to check voltages across the pins of the sound connector and was getting around 1 to 2 volts across pins when music is playing. when I stopped the music, the voltages eventually dropped to 0. It seems strange as I would of thought I would get no voltage at all if there was logic board damage so was wondering is this a hardware fault (logic board) or is there some software issue (software reset) as to why the sound is not working.

    I can not run a AHT test as I do not have the original disk for my mid2010 mac so am a bit stuck.

    If anyone has any ideas or possible fuse locations on the board I could inspect I would be very grateful.

    Also just to add I cleaned the logic board with contact cleaner and compressed air after the tea spill as there was slight green corroding on some parts but it all came off and there is no obvious sign of water damage or burnt marks on either side of the logic board.

    Thanks in advance and praying I do not need to replace a logic board :(
  2. viper8804 thread starter macrumors newbie

    Nov 11, 2012
    Just to add:

    the "Power on self test" shows as passed under diagnostics in system information however I have noticed I do not hear any chime or beeps upon startup.

    Does anybody no if the chime will only play out of the right speaker as I know for sure the speaker on the underside of the logic board works but I hear nothing on startup?

    If anybody has a schematics diagram for my 2.66ghz logic board, I would be very grateful if you could send it over to me as I am not sure what components I should be looking at on my board to see if they are damaged.

    Thanks again

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