Hello Macrumors members!
So I've bought a few iMac fans from Aliexpress because I needed good quality, silent, blower style fans for my compact Windows PC. What I've ordered are two iMac 21.5 fans and one for the 27 inch model. After carefully attaching a compatible connector for my system, I tested the fans. The two smaller ones work flawlessly but the larger one only works at it's max speed for some reason. I suspect (and hope) it's maybe a PWM or tachometer sensor issue, but wanted to ask if you have any experience with this:
Since the two smaller ones work properly (variable speed, depending on load) do you think the larger one is rather faulty Or it's circuitry inside is different and the speed is managed somewhere on the 27" iMacs main board rather than in the fan?
Edit: the fan models are for iMacs from 2012 and newer
So I've bought a few iMac fans from Aliexpress because I needed good quality, silent, blower style fans for my compact Windows PC. What I've ordered are two iMac 21.5 fans and one for the 27 inch model. After carefully attaching a compatible connector for my system, I tested the fans. The two smaller ones work flawlessly but the larger one only works at it's max speed for some reason. I suspect (and hope) it's maybe a PWM or tachometer sensor issue, but wanted to ask if you have any experience with this:
Since the two smaller ones work properly (variable speed, depending on load) do you think the larger one is rather faulty Or it's circuitry inside is different and the speed is managed somewhere on the 27" iMacs main board rather than in the fan?
Edit: the fan models are for iMacs from 2012 and newer