iMac fan going *mad* at startup

[Insulin Junkie]

Folks =)

My GF reported to me that her iMac's (new model) fan will often 'go nuts' at startup, and get extremely loud, only seconds after start-up and stay that way until the computer is shut down. I've fallen witness to this only once (and damn that thing is loud, sounds like a plane taking off), but she tells me it's happened at least five more times since. When it happens she shuts the computer down and restarts it, usually causing the issue to disappear, though today she tells me she had to shut the computer down three times before the fan reacted normally.

Anything I can do to help, or does the machine need to see an Apple employee?

Thanks for any advice.

 

[airjuggernaut]

Folks =)

My GF reported to me that her iMac's (new model) fan will often 'go nuts' at startup, and get extremely loud, only seconds after start-up and stay that way until the computer is shut down. I've fallen witness to this only once (and damn that thing is loud, sounds like a plane taking off), but she tells me it's happened at least five more times since. When it happens she shuts the computer down and restarts it, usually causing the issue to disappear, though today she tells me she had to shut the computer down three times before the fan reacted normally.

Anything I can do to help, or does the machine need to see an Apple employee?

Thanks for any advice.

Hey, your iMac's PRAM (parameter random access memory) might need to be reset.
The PRAM typically holds the information that is needed for startup and other things. Resetting it might help get rid of some incorrect value in you're PRAM that is causing your iMac's fans to go crazy.

Follow this guide on Apple's support database http://support.apple.com/kb/HT1379 to reset your PRAM

If that dosen't work then something is wrong with your iMac's thermal sensor and you should goto your nearest Apple store or Apple Authorized Service Provider to have it fixed or checked out.

Hope this Helps

 

[Insulin Junkie]

Thanks much,... totally forgot the PRAM reset is an option. I'll relay that to her and report back if the issue resurfaces.