Question Powering fans

Tobaewan

Reputable
Oct 23, 2019
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I have a 360mm AIO and I have the fans plugged into a little 4 way hub that came with it. Well one fan is spinning a little slower than the others. Does this mean the hub is going bad? How does one motherboard fan header deal with providing enough power for 3 fans? Is it ok?
 

kanewolf

Titan
Moderator
I have a 360mm AIO and I have the fans plugged into a little 4 way hub that came with it. Well one fan is spinning a little slower than the others. Does this mean the hub is going bad? How does one motherboard fan header deal with providing enough power for 3 fans? Is it ok?
You haven't provided enough info to answer your questions.
One fan spinning slower may mean that the FAN has higher internal friction.
The power question will require research on your part. You need to find the amperage rating of the fans. Add that up. Then look in the user's manual for your motherboard. It should identify the maximum amperage allowed on a fan header.
 

Tobaewan

Reputable
Oct 23, 2019
34
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4,535
You haven't provided enough info to answer your questions.
One fan spinning slower may mean that the FAN has higher internal friction.
The power question will require research on your part. You need to find the amperage rating of the fans. Add that up. Then look in the user's manual for your motherboard. It should identify the maximum amperage allowed on a fan header.
Ok they are all brand new out of the box and sometimes when the cpu starts getting hot and calling for maximum cooling two of the fans will be spinning but one isn’t doing anything.

I will look up the amperage right now. Thanks for the response.
 

Tobaewan

Reputable
Oct 23, 2019
34
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4,535
You haven't provided enough info to answer your questions.
One fan spinning slower may mean that the FAN has higher internal friction.
The power question will require research on your part. You need to find the amperage rating of the fans. Add that up. Then look in the user's manual for your motherboard. It should identify the maximum amperage allowed on a fan header.

The fans are be quiet pure wings 2 120mm and there is 3 of them, I couldn’t find amperage draw on the 120’s but best I can tell the 140’s is 0.9? So I assume they are probably pretty close. As far as I can tell each fan header on my motherboard is 2A so that means that the header can not provide the 3A all 3 fans would need…correct? So maybe plug two into the hub and the third into another header? Or am I looking at this wrong?
 

kanewolf

Titan
Moderator
The fans are be quiet pure wings 2 120mm and there is 3 of them, I couldn’t find amperage draw on the 120’s but best I can tell the 140’s is 0.9? So I assume they are probably pretty close. As far as I can tell each fan header on my motherboard is 2A so that means that the header can not provide the 3A all 3 fans would need…correct? So maybe plug two into the hub and the third into another header? Or am I looking at this wrong?
The amperage is written on the fan.
 

kanewolf

Titan
Moderator
ok ok 0.30A so 3 of them would be 0.90A so a 2A header should easily be able to power all 3 which means my little header is probably bad in some way. Thank you so much for leading me down this path haha sometimes you just need an outside view
If the board is bad, you can test that by swapping which port the "bad" fan and a "good" fan are plugged into. If the symptom is the same it is the fan, if it moves it is the port on the controller.
 

Paperdoc

Polypheme
Ambassador
You missed what kanewolf was getting at. If one fan of a new set of three is running slower than the others or even STOPPPING, that FAN is faulty. There is NOT likely a problem with the mobo fan header. You CAN test that using another mobo fan header, but you'd have to ensure that the speed control signal it is sent from the original and alternative the headers is the SAME. It does appear very suspicious to me that the slow or stopped performance is apparent when your system is hotter and the other fans are running fast -that further indicates a faulty fan.