What are the chances of a CPU fan malfunction?


Jul 30, 2014
Good day to you all,

I do consider myself a DIY solver when it comes to tech problems, but this time I'am truly stumped. I really need some suggestions.

Problem: Laptop fan has suddenly started operating at full speed. And I can't seem to find a reason behind it.

System: ASUS UX303LA, i7 4510U, 6GB (4+2), 250GB 850 Evo.

A lengthy read, but i'm giving you as much info as i can.

So around a week ago I was chilling in my living room reading, and my system was right there next to me, lid open and on Win desktop, and all of a sudden the fan spins up really fast. So I take a look in task manager and I see nothing (intensive) running, feeling rather puzzled I go into HWMonitor for a peek, temps are good, (30-40's), CPU utilization is ~0%, everything checks out. Except CPU fan, which is displayed as running @ 25500 RPM! Good lord! Obviously showing inaccurate readings, I download SpeedFan for clarification. RPM is hovering in the 4300 range (maxed out).

This problem seemed to be intermittent, sometimes after a shutdown the usual fan profile for the laptop would be used on next start up. Then, after a short while (maybe 10 mins, maybe an hour) it would whir up like a tornado again never to slow down. Now, as I'm writing this, no matter what I do it's 100% all the time. It's either off or on full blast.

I think it's irrelevant, but I will say now that this laptop is second hand, about 3 months ago It was bought cheaply because of hinge failure and cracked LCD. I fixed it up & cleaned thoroughly, along with new hinges, LCD Lid, CPU heatsink. So I can say with certainty that the problem does not lie with overheating. It's as clean as a whistle inside. [The plan was to sell it - as i could make a nice profit, but because it's such a nice machine I kept it as my daily driver.] After the new components installed I ran CPU stress test to ensure cooling was acceptable. All was good, temps, fan profile ect ect. Even stressed out, the CPU would be ~70-75C and fan @ around 3600 RPM which is ~85%.

In the 3 months I've had it, it's been used it everyday from this point, there has never been a problem with overheating or the fan profile. I use the laptop for CFD, FEA, CAD and some other aerodynamic programs. Which can be CPU intensive. Just one day, the fan decides to go loopy on me.

So here is a list of things I tried, I have tried to put them in order I did them.

>Restarted system - No change. (fan didn't even slow down or turn off)
>Shut system down fully and turned back on - Fan stops when off, but when power on fan spins up to full whack.
>Changing between high performance, balanced and power saver profiles - makes no difference.
>Adjusting via fan control software (SpeedFan) - As far as i can tell, the motherboard doesn't support fan control.
>Updating/removing ASUS drivers via Device Manager and through ASUS website - No difference
>BIOS is up to date, also no option for fan control in there.
>Stressing the CPU to try get the fan to respond somehow - nothing
>Leaving it sitting for hours to see if it stops - nope
>Restoring to a previous Win 10 build - nope
>Reinstalling Windows 10 completely - nope, one piece of additional info is that the fan spins up to max even before windows is loaded, as soon as" press F2 to enter BIOS" screen is displaying

So do I have a hardware problem then? Is my fan broken? I always considered fans to be a rudimentary component, unlikely to malfunction as there isn't much to go wrong! Am I misunderstood?

Any suggestions/advice would be greatly appreciated



Jul 30, 2014

Yes, unfortunately. (In fact, it spins up even before I can get into BIOS.) Which kinda leads me to this conclusion.

PS. me too!

I understood they can fail, but it seems strange it would go in this manner. Maybe shows my ignorance :)

Ok so, as for a solution, I've been hunting and found a replacement. It will be purchased in the next few days but "could take 3 weeks to get here" from Asus. I will update the thread as required. Here's hoping!

Thanks for input.