iMac fan problem-- please help

[Heshacherr]

The fan of my 27" late 2012 iMac has been making a very loud noise. I took it to an Authorized Apple Service Provider (unfortunately there're no Apple stores in Singapore, where I live). To make a long story short, the technician informed me that there is a problem with fan sensor and the solution to that is to replace the logic board, at a cost of ~$1000. This cost seems very unreasonable to me.

Any advice on how much this type of thing should cost as well as about any workaround (I read somewhere that there may be ways to regulate the speed of the fan through some software addon, for example) will be greatly appreciated!

 

[BrianBaughn]

To get good responses perhaps you shouldn't "make a long story short" and provide some actual details.

 

[Heshacherr]

"to make a long story short" was trying to save readers the frustrating details of my interactions with the Authorized Service Provider, who are the only people that one can turn to in Singapore as there is no Apple store here yet. The provider provided extraordinarily frustrating service interactions. Those seem irrelevant to my question.
Any advice on how to handle this (or questions on what additional info is needed) will be appreciated.

 

[briloronmacrumo]

Maybe share with us which fan is failing( iMacs have several ). That might help with a follow-up question which is: where is the fan sensor for this fan located? ( i.e. on the motherboard, attached to the fan, etc. ). Another question is: did the technician explain the reason for a motherboard replacement versus a simple fan and sensor replacement? I haven't priced motherboards but a price of $1000 seems a little high. What seems unreasonable is not the price for the motherboard( because presumably this is hardware plus labor cost - another question you could clarify ) but why they can't do a component replacement ( which would cost less ). My sense from the limited information is you are getting poor and possibly mis-leading /fraudulent information. A typical 2012 iMac 27 inch fan has one simple connector to the motherboard. Maybe you've checked out the fan replacement video on iFixit( https://www.ifixit.com/Guide/iMac+Intel+27-Inch+EMC+2546+Fan+Replacement/15761 ) or priced parts via search engines ( and that is more information you could put in your post ). A quick search on ebay shows motherboards for your iMac at less than $500 ( http://www.ebay.com/itm/iMac-27-201...774717?hash=item2109e2bafd:g:aBcAAOSwzgRWul-W ). Found this with a simple Google search. Might want to show your tech these prices and ask him/her to itemize the costs.

Anyway, now you know some of the questions and answers you might want to share if more help is needed. Your original post truly lacked any details and details are necessary if you really want help.

 

[Heshacherr]

Thanks a lot for the very helpful reply.

 

[chscag]

Your 2012 iMac only has one fan. Prior models had three. The loud noise you describe... is it the fan running at a high RPM or is it a hardware noise (rattling, scraping, etc)? The reason I ask is because the temperature sensor may be OK and the fan itself is defective. (dried out bearings, dirt clogged)

The app you asked about to control the speed of the fan is called "Macs Fan Control". Download from here.

 

[curtvaughan]

Before purchasing new hardware you might see if vacuuming the machine's vent holes fixes the problem. Lent and dust can easily block adequate air to cool the dense hardware packaging in iMacs.

 

[wlossw]

Step 1: determine if fan is damaged in some way. Is this the cause of the noise? If so, replace fan.
Step 2: If noise is caused by fan spinning quickly rather than being broken, install SMC fan control and manually adjust fan speeds.