Fan always on - Mac mini 2012

Hey, The fan unit is ok - I've even replaced it!

The cable is not damaged.

I put the old HDD back in but now I'm thinking whether I should reset the SMC with the old HHD in - Haven't tried that.

I'm wondering whether this is a firmware compatibility issue?

The newer units require the special Apple HD with the internal thermal sensor (one for one). When replacing the HD for a SSD you need to install either a software app to control the fan or add an external thermal sensor to replace the one that was inside the HD. Frankly, we just add the SSD (dual drive setup) or we replace the HD for a SSHD unit (our current direction when we need to repair a mini).

And yes you likely need to reset the SMC after swapping the drives around. Sure, you could also check the firmware. The '12 units don't currently have any updates that I know of. Here's the Apple TN to double check what your system has: EFI and SMC firmware updates for Intel-based Macs.

Hi. Can you believe I this still hasn't been resolved. I'm on the edge of desperation! I put the original HDD back in and did a SMC and PRAM reset and the fan keeps running at full speed! I noticed that the fan socket left clip is broken, but this is just a clip to hold the plug in? The 4 fan connectors are perfectly fine.

Any ideas?

thanks

Ouch! it maybe the connection is not sound. You do need some pressure to hold the contacts firmly together. You could also have lifted the contact from the logic board so the connecter its self is bad. You'll need to repair the connector some how. I would recommend you find some one with the skills to work on SMT components and can replace the connector for you as this is not something I would even try my self (my eye's can't see this small stuff very well any more).