Display Screen Proximity?
Hi, recently my iMac CPU fan (monitored through iStat Pro) spins up to max speed (around 3800 r.p.m) and sticks there untill i either sleep, restart or shutdown completely. The fan often spins up when waking the computer from sleep or it occasionally does it completely randomly when working.
I've tried resetting the PRAM and NVRAM to no avail. I'm running the latest version of OS X (10.7) and the most up to date firmware.
I've searched through threads and there seems to be a consensus that it could be a hardware fault with a sensor. From what i can understand, this then tells the fan controller to max out because of an erronous reading from a sensor. I've downloaded a program called Temperature Monitor and compared readings for normal useage and for when the fan is maxed out. When the fan is maxed out, a reading from the "Display Screen Proximity" is absent from the list.
I was wondering if this is a sensor and if it is what it actually does? If this is indeed a sensor, would this be causing my fan to stick at full speed?
I can upload screenshots of the readings for both coniditions if required.
I've been into the Apple Store and they ran a hardware test for which everything reported fine. Due to the random nature of the problem, I could not get the fan to max out in presence of the employees. If it's just a case of a faulty sensor, I can hopefully take it back in and they can replace the faulty sensor at a low cost.
Thanks,
Tom Barrack.
Apple iMac 24", Mac OS X (10.5.6)