HDD fan spinning at full speed on imac 2006 after cpu upgrade

[chriz74]

Does anyone have any idea why? I have a 2006 imac 4,1. I upgraded the FW to 5,1 and was waiting for a core 2 duo cpu to arrive in the mail.

When it finally arrived I disassembled the mac to switch the cpu. Everything works but now the HDD fan is running full speed and very noisy.

I don't understand what's going on, afaik I didn't touch the HDD temp sensor at all. Reset SMC and NVRAM didn't solve the situation.

Any clue?

 

[robeddie]

Obviously something got messed up with the sensor, but just Download Macs Fan Control. Then set the hdd range from about 42c to 60c.

https://www.crystalidea.com/macs-fan-control

 

[chriz74]

i'll open the mac tomorrow to see what, if anything, happened to the sensor

 

[nambuccaheadsau]

Make sure all cables are correctly connected, nice and firm. This can happen if sensors to fans etc. are not re-attached correctly.

 

[chriz74]

Opened it, everything seems fine. I could set the fan to s.m.a.r.t. with SSD fan control but now also the CPU fan is running at full speed. Reset SMC doesn't cure it.

 

[chriz74]

I tried smc fan control. It shows that the ODD fan is at 0 RPM. Could it be it is failing and so the other fans are running at full speed?

 

[chriz74]

I used macsfancontrol to silence