MacBook only run if fan are 100%

Discussion in 'MacBook' started by ITAngel, Jun 8, 2012.

  1. ITAngel macrumors newbie

    Jun 8, 2012
    Hi guys, I have a MacBook that will not boot if the system is on normal setting. It gets to the mac grey apple logo with the gear running and shut off. For a while it ran to the desktop and after 2mins or so it shut off. Finally I was able to do a SMC reset and it leave the fan to run at 100% and it seems to work that way but the fan stay running non-stop that way. If I remove the battery, hold the power button for 5sec and put the laptop back together and get it started. Well the unit will then shutdown unless I do the smc reset were it keeps the cpu fan at 100%. Any idea? I install Mac OsX again on it too just in case.
  2. unixperience macrumors regular

    Jul 21, 2010
    when you boot it start it in verbose mode command+option+v this gives a long list of processes that have to start in order for the laptop to work,, it may be that it stops at a certain line everytime, this could be the problem.

    i would then recommend getting an application, or two (both are free... i don't know if they are in the apstore though... but they work fine and are safe i've used both of them as long as i've had my comp, of course upgrading versions as they became available which was after every new mac computer is released). the first being smc fan control, it allows you to set the slowest speed your fan ill run at, it also does give the temperature near the cpu chip. watch that and see how hot it gets

    temperature monitor: this reads all the temp sensors in the mac and can plot them over time, again this is jsut to figure out why your fan is so high, are there abnormal temperatures?

    and monitor cpu usage in activity monitor. the fans typically only start whirring with high cpu usage, so see if there is something eating up cpu (activity monitor is a builtin program, its in the utilities folder, i seem to find a lot of people don't know it exists) then make sure the droopdown list in the opper right hand corner says "all proceses" not just "my processes" see if there is anything that takes up a large amount of CPU

    if any of these numbers from any of these programs seem high... you can get an idea of where the issue lies.
  3. ITAngel thread starter macrumors newbie

    Jun 8, 2012
    Ok did what you said these are the stuff I did and discover;

    0. Install new CPU Thermal Paste Arctic Silver 5
    1. Install Mac OsX 10.6.3 Retail, updated to 10.6.8 full update, everything installed from optional stuff to extra.
    2. Installing it did nothing to fix the issue even with full updates.
    3. Ran Apple Hardware Test from a Retail DVD OsX 10.6.6 for a quick 3mins check and saw nothing as far as problems go.
    4. SMC Fan Control didn't report RPM or anything kept at Zero. :confused: -1rpm in some cases but the fan is running at full speed.
    5. At the last minute being the way the laptop was I ran it for like 10-15mins before a full batter went dead and had the green light blinking.

    Not sure what to do next, every time I change it from doing the Shift+Control+Power and do the power reset back to normal the system will not boot. But if i do the 3 finger solute it then boot with fans at 100%. Any idea or tips from anyone? Thanks!
  4. tom vilsack macrumors 68000

    tom vilsack

    Nov 20, 2010
    ladner cdn
    Im curious how you do a smc reset to make the fans run at 100%???

    After i bought my macbook last week i did a pram and smc reset,but fans only runs hard if using utube ect....
  5. ITAngel thread starter macrumors newbie

    Jun 8, 2012
    I was following instructions from only by holding the shift+command+power button until the light on the laptop blink a few times and shutoff. Then I press the power button to see if it boot or not. Until I hear the fan kicking in at 100% full speed then I know I did it. Is weird it takes it from time to time. Not if that is a smc reset or if that is something totally different. I might need to record it and put it on youtube so you guys can see what i mean.

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