Desktop Fan spin direction - sucking in air instead of pushing out hot air

[GROverloaded]

Hi,

My Desktop system has 2 fans, one at the bottom (which should ideally take in air), and other at the top - system fan (which to push out the hot air that has raised to the top).

Sometimes, during the operation of the system (i.e. when using it, and it goes to sleep/hibernate mode), the top fan reverses direction of spin! It is taking in air instead of pushing out the hot air.

This causes my system to reach temperatures of 75-90 degree Celsius! (Windows had to shutdown my system because the temp once exceeded 90).

This is a relatively new system (8-10 months old). 

I have even tried getting some software that checks/controls fan speed, but these only seem to detect/control the bottom fan. 

Is there any way i can solve this at home (any software to check direction and spin of both fans), befoire going to any service center?

[savvy2]

never seen this nor seen this  any forum on topic, this.  wow fun !  love the odd.

NO PC even told, what is it?

First off the polarity to the fan is wrong.

1: wrong fan not HP.

2: or plugged in backwards.

3: or is normal when BIOS runs fans it makes DECISIONS based on overheating, really  the most key part is there if HP is fully authentic  parts. inside, I can not see inside your PC and would every time, reading those PN/ stickers on fans or its wire sets.

HP and all TOP OEMs the BIOS blocks your software hacks even to the point of the bios controls use  secret ID code.

that is correct, they block you so you do not BURN UP a PC in warranty,  (frankly smart of them , imo)

80 or 90c is way too hot, this CPU temps?

is PC a real DESKTOP or fack AIO??

a real desktop has a PSU fan and  1 or 2 or more case fans and 1 CPU fan and  GPU fan,(cards)

mine real desktop has 5. a DIY PC Asus based, I have Z600 too  and others. here all real, not AIO

but overheating has 3 causes.

1; lint pack up, in fans and heatsinks.

2: TIM bad, the CPU thermal grease is bad, get SHIN ITSU  and win. (intel use this , a secret)

3: heat sinks loose. (mounts bad etc.

4: case fans dead. in many cases of real Desktops only one fan needs to be good, but NO PC told so cannot advise.

the total heat load inside the PC dictates fans needed.  (like my 250watt GPU and 100watt CPU.) see?

some PCs like this only have 100watts total heat load, slow PCs, slow 3d and Energy star loved.

5:

sorry never seen any fan turn backwards , unless, it is COASTING,

when your  fan turns backwards simply pull its power cable if  is coasting it will just keep doing that.

if  fan stops the BIOS is funky. NO comment there, over my pay scale 0.

good luck but do tell more and what PC and if the cable pull works.

[GROverloaded]

Thank you Savvy2, for the detailed explanation.

My system is a Desktop, model = HP Pavilion Gaming Desktop TG01-0xxx series

The odd thing is the polarity changes mid operation! i.e. when i start the system is fine. but after a few screen_savers/sleeps, it just changes polarity then.

And my temperature I mentioned, is probably the CPU temp (Windows said that it touched 90C once and that's how I came to know). I only recently got MSI Afterburner to see the CPU temps, and now when playing games (after I check that both the fans are running properly), the temp maxes out at about 65-69C. 

BUT when the fan spin in wrong direction it goes above 70-75C.