8 Replies Latest reply: Jul 22, 2007 6:14 AM by den.thed
Arnd Kaiser Level 1 Level 1 (5 points)
Hi,

for a couple of days now, my iMac (Core 2 Duo, 8 months old) won't start up anymore when I press the power button. However, if I press and hold the power button for about 5 seconds, then press it again, the computer will start. Has anyone seen this before?

I know the trick of pressing/holding the power-button to force shut-down. So could this in fact mean my iMac didn't shut down properly? Just guessing.


iMac 2.16 GHz Intel Core 2 Duo   Mac OS X (10.4.10)  
  • Steve Anderson5 Level 1 Level 1 (85 points)
    Hi,
    Try unpluging your iMac power cord form the wall outlet for a minute then plug it back in - try power button. This worked for me.
    Cheers,
    Steve
  • den.thed Level 7 Level 7 (24,510 points)
    Have a look here > How to reset the System Management Controller < <br>
    17" iMac Intel Core Duo - 2GB Ram -   Mac OS X (10.4.10)   - Maxtor 300GB FireWire - Creative Inspire 2.1 - 2G Nano
  • Arnd Kaiser Level 1 Level 1 (5 points)
    Hi,

    I tried this - twice - but it didn't help. After resetting the SMC, the iMac would start fine once but after the next shutdown, it would not react to the power button again.

    I noticed that after shut down, the fan is still on...
  • den.thed Level 7 Level 7 (24,510 points)
    To shutdown your iMac go to: "Apple / Shutdown" from the drop down menu bar.

    To sleep your iMac go to: "Apple / Sleep" from the drop down menu bar or the auto sleep funtion!

    Using the power button to shutdown the iMac can cause loss of data, file corruption and damage to your HD.

    Go to: "Apple / System Preferences / Energy Saver / Options" Look at "Allow power button to sleep the computer" If the the box is checked then the power button will sleep the computer the first time you push it, then hard shutdown the next time you push it.

    Dennis

    17" iMac Intel Core Duo - 2GB Ram -   Mac OS X (10.4.10)   - Maxtor 300GB FireWire - Creative Inspire 2.1 - 2G Nano
  • Arnd Kaiser Level 1 Level 1 (5 points)
    To shutdown your iMac go to: "Apple / Shutdown" from
    the drop down menu bar.

    To sleep your iMac go to: "Apple / Sleep" from the
    drop down menu bar or the auto sleep funtion!

    Using the power button to shutdown the iMac can cause
    loss of data, file corruption and damage to your HD.


    Go to: "Apple / System Preferences / Energy Saver /
    Options" Look at "Allow power button to sleep the
    computer" If the the box is checked then the power
    button will sleep the computer the first time you
    push it, then hard shutdown the next time you push
    it.

    Dennis



    I know... But what's that got to do with my (possible) SMC failure? I wonder, apart from this:

    How to reset the System Management Controller < </div>

    Is there any "hard reset" that could fix it? Or does my iMac need repair?
  • den.thed Level 7 Level 7 (24,510 points)
    Run both Hardware and Repair from your Install Disk 1, see the instructions in the articles below!

    Intel-based Macs: Starting up into Apple Hardware Test

    Testing and repairing from Disk 1

    17" iMac Intel Core Duo - 2GB Ram -   Mac OS X (10.4.10)   - Maxtor 300GB FireWire - Creative Inspire 2.1 - 2G Nano
  • Arnd Kaiser Level 1 Level 1 (5 points)
    Dennis,

    I did as recommended and ran the hardware tests. It didn't reveal any problem. However, I did some tests with and without connected devices and found a firewire audio device to be the reason for my iMac not shutting down completely. The problem disappears when this device is not connected to the Firewire port.

    I can't see the connection between this device and a SMC problem but I will do some more tests with this audio device, also on another Mac.

    Thanks for your help!
    Arnd
  • den.thed Level 7 Level 7 (24,510 points)
    The issues may only be connected by an improper shutdown (power button) with device(s) in use. Sounds like you have worked thru part of the issue, I can only test the FireWire devices I have here. All is OK if I eject and shut down my External HD, eject and disconnect any of my camera's and iPod befor shutting down my iMac!

    More info for FireWire:

    USB and FireWire Quick Assist

    FireWire: Frequently Asked Questions

    Dennis

    17" iMac Intel Core Duo - 2GB Ram -   Mac OS X (10.4.10)   - Maxtor 300GB FireWire - Creative Inspire 2.1 - 2G Nano