Laptop CPU fan not working

VsYK

Honorable
Nov 23, 2013
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10,510
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Hi, I am currently trying to fix an Asus UL30a Laptop. All works great apart from one thing, the CPU fan refuses to spin.

Now, I have purchased 2 replacement fans from 2 different sellers to rule or try to rule out dud fans. Anyways, I don't know if this laptop fires up the cpu fan when it gets too hot or from boot. But I left laptop on for 5 miins without it & it decided to switch itself off so I presume its from boot?

I have tested the 5V & 3V pins & they both give that power. Connected a 5v fan it & it fired it up from boot. Connected one to both yellow, red & again it fired up.

The only thing I cant test is the PWM (blue wire) which is basically the controller for the fan.

It has latest 212 firmware & everything else works great. I even went to the extreme lengths of getting a hold of 2 identical motherboard & DC boards & switched them around & I get exactly the same thing.

Now I'm not 100& sure but how can I test the fans i purchased? I don't have any other hardware that uses the PWM to rule out its not the fans but 2 from separate sellers, both cant be faulty.

Your help would be greatly appreciated.

Thanks in advance!
 

VsYK

Honorable
Nov 23, 2013
8
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10,510
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Yep, I had the both boards connected & keyboard, touchpad & everything else wired up as if it was in the case. I even put it all back in the case just to rule it out with the keyboard not clipped in fully so I can see the fan & still nothing. I didn't leave it until it got hot because I didn't want to risk damaging it as the boards are hard to come by!

Just had a new fan come today, used but from an identical laptop that broke & I was assured it was working so its not the fans. I don't know if this laptop model only fires up the fan if it gets beyond a temp to save battery or not. I've sent a support ticket to Asus & asked them because everything works but it just refuses to spin on 4 different fans all purchased & stated working & New!
 

ffg7

Honorable
Moderator
the fan won't run right away as had to replace a customer's fan & when I did, it did not kick in for a while as the laptop was still somewhat unassembled. even assembled it took a while before kicking in. I think that laptop was an asus too.