Fans,Headers or PSU

i've just started having this quirk with my rig the last couple of days, and looking for some ideas as to what the issue could be.


rebuilt my rig the other week with a p5q-deluxe as the previous mobo was starting to fail. now haven't been home much recently due to work. friday night booted up and noticed that neither intake or extract fans were going (more the intake as it's an led fan) but the fan on the cpu was fine.

so gave the extract a little spin up with a finger and it started to go and the led intake fan kicked in to. now if i do a reboot the same happens.

now the only things i can come up with are.

a. that both fans are getting a bit worn, although i can't believe that it's both of them 1 ok but not 2.

b. there is an issue with the motherboard fan headers. are all fan headers commoned up on a mobo? or are the case fan headers seperate from the cpu fan header, or are they all seperate? main reason i would think of this is that it is both fans that fail to start, and if there was a problem at one header would it replicate on the other? the other thing is that when i spin up the extract fan both of them kick in, but lastnight i noticed that for a few seconds 1/2 of the led's on the intake were flickering (would that to point c. the psu?) but then settle down.


c. lastly the only other thing is the psu, i don't thinks so but not sure. it's an ocz evo720, and all thats plugged in is the 24pin mobo/8pin cpu/ 6pin gfx and 2 sata ppower for 2xhdd and dvd.


any way to conclusively prove what it might be without having to use any spares - which i don't have at the moment. really don't want it to be either the mobo which is only a month old or the psu which is quite a bit older but still fine. if it's the fans - then fine i can grab a couple of them no probs.

i would check the fan headers are kicking out 12v with a multimeter if possible, or try the cpu fan on those headers ?

Try disabling/changing Q-Fan or whatever the fan control settings are in bios. Your fans probably can't run at the low voltage being given.

It's probably Q-fan undervolting the fans. Is the system actually overheating? Or are you just concerned about a possible fault/anomaly? Take a peak in the BIOS settings in any event.

Quote:

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Originally Posted by GoNz0

i would check the fan headers are kicking out 12v with a multimeter if possible, or try the cpu fan on those headers ?

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will do, found a molex > header converter with bare ends so will use that to adapt to my meter.

Quote:

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Originally Posted by sadbuttrue

Try disabling/changing Q-Fan or whatever the fan control settings are in bios. Your fans probably can't run at the low voltage being given.

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hadn't thought of that, will check when i check the voltage.

Quote:

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Originally Posted by aidanjt

It's probably Q-fan undervolting the fans. Is the system actually overheating? Or are you just concerned about a possible fault/anomaly? Take a peak in the BIOS settings in any event.

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it's not overheating at the moment as i hadn't put the side back on :stupid:, will check bios settings but don't seem to remember the fans not operating when i first rebuilt it. so want to check to see if it isn't a problem with the headers. as i said i can't see it being both fans gone at the same time.





edit.

just checked voltage with the fans running and was getting 12.2v, the bios was reporting 12.29v so with my meter set on 1 decimal place and not 2 i would say that it was pretty accurate. just done a shutdown and reboot and the fans started no probs:confused:, so will have to try later after the pc has been off for a while.

checked the q-fan settings and it's already disabled on the cpu and chassis fans.


anything further i can check?

If you deliver 12v directly to the fans from the PSU and they still don't spin up, then it's a case of a pair of faulty fans. As unlikely as it seems, that's the logical conclusion. For whatever reason, the fans aren't getting enough current to kick start their motors.

Quote:

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Originally Posted by aidanjt

If you deliver 12v directly to the fans from the PSU and they still don't spin up, then it's a case of a pair of faulty fans. As unlikely as it seems, that's the logical conclusion. For whatever reason, the fans aren't getting enough current to kick start their motors.

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well going to pick up a couple of fans later just to eliminate/prove them. is the 12v for the fan headers not regulated by the mobo or does it get routed direct via the 24pin?

Yeah, the motherboards power regulation circuits provide the fans power from the 24pin ATX connector. 3pin fans should be fine. Akasa fans almost always provide 3-pin to 4-pin molex connectors, which adds a bit of flexibility.

well i never managed to get any fans earlier, i broke my rule of not goin to pc ****eworld to get a couple of akasa fans but they didn't have any except some crappy jeantech ones.

so brought a fish tank for my little 'un instead........who needs a bank to rob them when u got a wife and kid(s) :)


so will try again tomorrow.......................if i get away from cumnock in time.