Plugging in power makes the fans go nuts

Discussion in 'MacBook Pro' started by carlosbutler, Apr 5, 2013.

  1. carlosbutler macrumors 6502a


    Feb 24, 2008
    London City
    Whenever I plug in the power, the temp sensor (according to SMC fan control) goes from ~40 up to ~90 in a second or two. I'm guessing the reading is completely incorrect.

    Thus the software thinks the machine is on fire, so the fans ramp up to take off speed and are constantly at max speed which is annoying. CPU is 0%.

    Anyone have any ideas what the issue might be. I can't seem to find any decent results in search engines.

  2. remzibi macrumors newbie


    Apr 6, 2013
    Middle Europe
    It is strictly electronic problem . First case is bad thermal sensor but I do not think so (one in MCU and other on mainboard) .
    Most possible problem with power supply of logic chipsets , looks like you should go to any Apple (good)service centre .
    I am afraid that replacing board will be solution.
  3. GGJstudios macrumors Westmere


    May 16, 2008
    First, ignore the post before mine, as that poster has been posting misinformation in several threads.

    If your fans are spinning up without increased heat, try resetting the SMC.
    (PRAM/NVRAM has nothing to do with these issues. Resetting it will not help.)

    If there is increased heat, follow every step of the following instructions precisely. Do not skip any steps.
    1. Launch Activity Monitor
    2. Change "My Processes" at the top to "All Processes"
    3. Click on the "% CPU" column heading once or twice, so the arrow points downward (highest values on top).
      (If that column isn't visible, right-click on the column headings and check it, NOT "CPU Time")
    4. Click on the System Memory tab at the bottom.
    5. Take a screen shot of the entire Activity Monitor window, then scroll down to see the rest of the list, take another screen shot
    6. Post your screenshots.
  4. carlosbutler thread starter macrumors 6502a


    Feb 24, 2008
    London City
    Ah-ha! I found out what it was. I installed Folding@home. I didn't realise it stayed at max research even after restarting a computer. Also, I didn't realise it didn't show under All Processes.

    To anyone reading this, always check All Processes ;)

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