Computer case fan 2 not working on both PC's

rdrennen12

Commendable
Jan 23, 2017
3
0
1,510
A while back on my wife's PC the front case fan (2) stopped working but still lit up with the LED lights. It did work on mine but I chalked it up as it possibly just stopped working.

Well today I re wired my PC and try and clean it up and now the same front case fan (2) stopped working for me as well, but the LED is still lit. At this point I figured maybe I am doing something wrong.

They are both plugged into the mobo on fan 2 and when going into the bios there is no sign of fan 2, 1 and 3 are present. They are three prong pins. Again when I first hooked everything up they both worked just fine.

They are both powered to the same power supply connector line with fan 1. Fan 3 on both have their own power supply line running to the power supply. Can that be the problem? Could both being connected to the same power line to the power supply not be enough juice for the two?

Maybe they both just stopped working and I am just losing my mind.

I have a ASUS 970 Pro gaming mobo
Both have AMD processors, one is eight core and other is quad core.

Thank you for your time.
 
Solution
OK now you've got me confused. First your orignial post says, "They are both powered to the same power supply connector line with fan 1. Fan 3 on both have their own power supply line running to the power supply. Can that be the problem? Could both being connected to the same power line to the power supply not be enough juice for the two? " Now your most recent post says all three are plugged into mobo fan headers.

There is one other mistake I have seen that I also hope you have NOT made. Some people have plugged an odd small connector on a set of output cables from a PSU into a mobo fan header, thinking that is involved in fan power and control. If you have done this, remove it immediately.

I REALLY hope that is wrong! You must NEVER...

Paperdoc

Polypheme
Ambassador
First of all, you seem to be missing a factor. For the mobo to be able to tell you the speed of a fan, it MUST be plugged into a mobo fan header. Any fan plugged directly into the PSU (as it appears your fans 1 and 3 are) will NOT have their speed shown nor will the mobo even know they exist.

Now, a fan that does not run (especially one you have had for a while) usually has worn bearings that cause too much friction and make it VERY hard to start up. As a check test, when the system is running but the fans in question are not, try gently pushing the fan and see it it starts and keeps running. If it does, that sort of confirms what I just said. If it simply will not start, shut the system down and again try to turn the fan with your finger. If it does not turn VERY easily, it is badly worn and seized. In either case, the solution is to replace the fan.
 

rdrennen12

Commendable
Jan 23, 2017
3
0
1,510




On both PC's fans are plugged into mobo and I can see fan speeds for fans 1 and 3. On both PC's fan's 2 are not working and are hooked to mobo as well. Its just odd that on both PC's that its the same fan not working. I will try and push start them and see if that helps. They are not even 6 months old.

 

Paperdoc

Polypheme
Ambassador
OK now you've got me confused. First your orignial post says, "They are both powered to the same power supply connector line with fan 1. Fan 3 on both have their own power supply line running to the power supply. Can that be the problem? Could both being connected to the same power line to the power supply not be enough juice for the two? " Now your most recent post says all three are plugged into mobo fan headers.

There is one other mistake I have seen that I also hope you have NOT made. Some people have plugged an odd small connector on a set of output cables from a PSU into a mobo fan header, thinking that is involved in fan power and control. If you have done this, remove it immediately.

I REALLY hope that is wrong! You must NEVER connect leads from a fan to BOTH a mobo header and a PSU output! Doing that could damage your mohbo's fan header circuits. If that is what you have done, DISCONNECT all those fans from the PSU. Connect them ONLY to mobo headers and see what is still working.
 
Solution

rdrennen12

Commendable
Jan 23, 2017
3
0
1,510
OMG I had the fans connected to MOBO and the molex connector to the PSU. I thought it had to be into both since well both are on the fans. I just have them connected to the mobo and all fans are working now on both PC's Thank you. I am a dummy.