Help! Fan on my iMac runs continuously

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nowis74 Author

Level 1

0 points

Help! Fan on my iMac runs continuously

Since this morning one fan on my 8-weeks old iMac runs continuously - without any obvious reason.

Thanks to iStat i know it is the fan "optical drive". (linked screenshots)

I did a SMC and a PRAM reset. With no effect.

I did a AHT. It reported one error: 4SNS/1/C0000008:TG0H--124

Can anyone help me?

thank

Michael from souther Germany

My iMac:

Modellname: iMac

Modell-Identifizierung: iMac12,1

Prozessortyp: Intel Core i7

Prozessorgeschwindigkeit: 2,8 GHz

Anzahl der Prozessoren: 1

Gesamtanzahl der Kerne: 4

L2-Cache (pro Kern): 256 KB

L3-Cache: 8 MB

Speicher: 32 GB

Boot-ROM-Version: IM121.0047.B1F

SMC-Version (System): 1.71f22

iMac, Mac OS X (10.7.4), BTO iMac 8 weeks old ;-(

Posted on Aug 22, 2012 8:35 AM

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Answer 1

RRFS

Level 5

4,522 points

Aug 22, 2012 8:57 AM in response to nowis74

I realize that Store locations are not convenient in Europe but you should take it in for service. 😟

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Answer 2

Allan Jones

Level 9

68,678 points

Aug 22, 2012 9:16 AM in response to nowis74

I did a AHT. It reported one error: 4SNS/1/C0000008:TG0H--124

That code indicates a bad sensor. When one sensor fails, the fan speeds increase to near maximum to avoid any damage by a heat source that is not longer monitored.

RRFS is right--you'll need professional help to repair. Nothing you can do via software or end-user trouble-shooting will correct the problem

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