MBP Late 2011 - no battery behaviour

Discussion in 'MacBook Pro' started by Cynic, Apr 24, 2012.

  1. Cynic macrumors newbie

    Apr 4, 2012
    Hi all

    I desperately need to know if this is normal behaviour for a late 2011 MBP 13". If anybody knows it will be greatly appreciated :) All a bit of a mystery to me I'm afraid!

    I have a macbook pro late 2011 13". I believe the battery is a dud (it will not charge at all). Seems to only give 3v out on some pins (this goes to 12.5 on some pins when the power is connected on laptop).

    To turn it on I must hold down the power button for a period of time and it works (with or without the battery connected). If I let the power button go too soon it will turn off.

    The machine also turns on and off briefly when you first plug the power connector in.

    It runs completely fine with the battery unplugged (up times of days+ no crashes & passes a linpack test). However it is only clocked at 700mhz and will not clock any higher... (no speedstep).

    If I leave the battery in then the machine will turn itself off after a random period of time. It is still only clocked at 700 mhz with the battery in & the kernel uses all of the CPU in Mac os (but this is not an issue in windows?).

    Any ideas?? Is this simply because there is no battery in the machine or is there something wrong with the charging circuit/SMC?

    If this is normal - I will buy a new battery! If not, any ideas how to fix it?

    Many thanks in advance! Really struggling to understand this behaviour.
  2. Gav2k macrumors G3


    Jul 24, 2009
    The machine is designed to use both hence the massive down clock. You need a new battery.
  3. Cynic thread starter macrumors newbie

    Apr 4, 2012
    Do you know if the behaviour is typical of a MBP with no battery or a bad battery?

    That is:

    holding down the on button in order for it to turn on (if button not held for long enough mac will turn off). That is on releasing the power button too early it turns off.

    mac turns on briefly and then off when the power cord is plugged in
  4. GGJstudios macrumors Westmere


    May 16, 2008
    No, that's not normal. Take it to Apple and have them check your battery and logic board.

    This should answer most, if not all, of your battery questions:
  5. Bear macrumors G3

    Jul 23, 2002
    Sol III - Terra
    The computer is less than a year old, so it is definitely still under warranty. Why didn't you just take it to an Apple store? They might've told you you need to pay for a new battery or they would have fixed the machine for you if it isn't just a battery issue.
  6. Cynic thread starter macrumors newbie

    Apr 4, 2012
    It unfortunately sustained some water damage.. and by some i mean a lot! So I can't get it repaired under warranty.

    I've cleaned it & have tested the components I can identify. There was some discolouration on the fuse closest to the battery, but this seems to be fine (it doesn't turn on at all if you remove said fuse).

    I'm guessing there is something not right with the charging circuit or the SMC. I've tried SMC reset but to no avail.

    It's a real shame as it runs fine - everything works but the battery & clock speed! Apart from obviously having to hold the power button down to get it to turn on!

    Anybody have any ideas of components which might cause these symptoms if they're faulty?
  7. GGJstudios macrumors Westmere


    May 16, 2008
    It would have helped if you had mentioned that in your first post. With water damage, all bets are off. It could be any number of components affected. Chances are very good that your Mac will not perform properly until it's repaired.
  8. Cynic thread starter macrumors newbie

    Apr 4, 2012
    I'd like to attempt to repair it myself! Is there a schematic for this model out there somewhere?

    Also - does anybody know which pins are which on the battery?


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