Question CPU FAN won't slow down

pc_gamer

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CPU fan speed is at 100% even if the temperature of CPU is below 20 degree
MB : M5A97 R2.0
CPU : AMD FX 6300
GPU : NVIDIA GeForce GTX 960
OS : windows 7 professional 64bit

Things I tried
changing the setting in Assus AI suite/fan xpert
Changing the settings via Speedfan
Changing the settings in bios (setting it to cool and quite then tried manual and standard method)

Also when I test the Fan via xpert the result shows at all power RPM is 6490 which is max. I've added all the screenshots below
I'm clueless what to do next

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Jul 31, 2019
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10
try
3.6.4 CPU Q-Fan Control [Enabled]
[Enabled] Enables the CPU Q-Fan control feature.


CPU Fan Profile
[Silent] Sets to [Silent] to minimize the fan speed for quiet CPU fan operation.
 

Colif

Win 11 Master
Moderator
Most likely, the thermal diode for the fan controls has failed. Or, the fan controller has failed. In any scenario where the system is not reliably reporting thermal readings,

(and the thermal readings on that architecture consists of thermal margin (Distance to TJmax) and NOT any specific temperature so whether a utility tells you it is minus twenty degrees, or forty degrees, or a hundred degrees, none of those is accurate. ONLY AMD overdrive or Core Temp with the "distance to TJmax" option enabled, will be accurate for thermal monitoring on that platform)

it will automatically kick the CPU fan to high speed or shut down. Could also be that the PWM controller on the motherboard has failed, in which case it would likely default to full speed operation.

Was this system working normally previously and then just suddenly started this behavior, or did you just put this system together or inherit it from somebody else?
 
Take the side panel off and take a VERY close look at all the capacitors on the motherboard. Look for any that are leaking or bulging. On a board with the probable age of that one, and having sat a year as well, it would not be unlikely.



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Also check for other signs of damage on the motherboard such as burnt or blistered spots, bulging or leaking capacitors, scratches that might have damaged one of the printed circuits or traces on the motherboard and any potentially broken or damaged solder points.
 

pc_gamer

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@Colif
PC could need a clean after 1 year off
Yes checked it, it wasn't crystal clear but it was good besides the first two days it worked flawlessly. will vacuum just to be sure

@Darkbreeze
nothing visible to the eyes but will check again while cleaning.

Thinking of getting another 4pin fan and check whether it's the faulty fan or motherboard
 
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Do NOT EVER vacuum inside your PC. Vacuuming creates static electricity which is the very LAST thing you want to ever do near any delicate electronics like a motherboard, graphics card, etc. Use compressed air either from an air compressor or canned air.
 

pc_gamer

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I got around cleaning my system, still, the issue is there, couldn't get my hands spare 4 pin fan connector to test out my theory. is there any other way to deduce what's wrong and why?
 

pc_gamer

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I just experienced something very peculiar, I turned off the cool n quiet via motherboard configuration for both CPU and chassis fan. all of sudden I can control the fan speed via Fan Xpert !! although CPU fan seems to turn off completely then rev up to full speed again and again for every 3 seconds. setting fan profile to turbo made it run around 4500- RPM. any other mode same issue
tried to set it manually , the same issue