Question about the bios chip

Discussion in 'MacBook Pro' started by Xylocaine, May 25, 2015.

  1. Xylocaine macrumors newbie

    May 25, 2015

    Can anyone confirm if this is the bios chip on the macbook pro (late 2011 model)?

    I'm speaking about the chip with 8 pins total (4 on each side) identified by the text 99CHN.

    Does every component ABSOLUTELY need to be taken out (other than the battery of course) before soldering a new chip on the board or can it be done as is by only removing the back cover?

    Thank you!


    Attached Files:

  2. Xylocaine thread starter macrumors newbie

    May 25, 2015
    I figured out that this was effectively the bios chip. Any recommendation about soldering tools/tricks or if it's absolutely neccesary to unplug every component before soldering a new chip to the board?
  3. dukebound85 macrumors P6


    Jul 17, 2005
    5045 feet above sea level
    The chips on the logic board need very precise soldering that can't likely be done by hand...
  4. Freyqq macrumors 601

    Dec 13, 2004
    What's your plan? curious. Is your bios chip defective, or are you replacing it with a different bios chip from a different chipset? You are trying to do something that is very risky, even under the best conditions.
  5. T5BRICK macrumors G3


    Aug 3, 2006
    Just disconnect the battery and you should be good. When removing the part, make sure you've got the right tools. If you're not careful, you'll lift the pads and then the logic board will be trashed.
  6. Xylocaine thread starter macrumors newbie

    May 25, 2015
    What tools would you recommend?

    I might file the legs to avoid using heated air and then remove the legs one by one to avoid damaging the logic board.

  7. Xylocaine thread starter macrumors newbie

    May 25, 2015

    I bought a defective unit to experiment with. I'll try to replace some components to practice! I might as well experiment with microchips programming but doubt I'll have enough time. I heard a lot of information can be stored on those atmel chips (they can retain memory for 100 years at normal temperature and apple could use those chips to store sensitive user data).
  8. Andropov, May 26, 2015
    Last edited: May 26, 2015

    Andropov macrumors regular


    May 3, 2012
    Well, not "a lot" really, just 8MB (in the newer Macs).

    However, be careful when soldering. These are very delicate components, so you definitely need some previous soldering practices (which I guess you already have).

    You don't need to take out any component (besides the battery) as long as they don't interfere with what you're doing.

    BTW, Apple should consider encapsulating this chip and its contacts to prevent unauthorized manipulation (most people don't do it for educational purposes).

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7 May 25, 2015