Strange fan behaviour

[Koiju]

Ok, I've got my PC part, put them in and plugged them in correctly (as far as I know), and am at the stage where you first turn it on.

I turn it on, and everything seems fine, the power light comes on, all fans turn on, HDD comes on, monitor gets a signal, I get the memory count, the CMOSS screen thingy flashes up, I get one and only one beep from the computer speaker. But then I notice somthing odd, my CPU and case fan are now both off! They come on, then turn off again imediatly. everything else seems fine though, everything else seems to have power (for the breif few seconds I let it be on before cutting the power of course, heh).

Anyone have any idea why they are doing this?

Oh, another thing, if I press the reset button, the fans wont go on and off again, I have to completely cut the power, then turn on again, and the fans will then do there little on-off trick.



Just in case, the stuff I got:

Asus Vintage AE1 Barebones System - AMD Socket 754

AMD Athlon 64 3000 Newcastle 130nm (Socket 754)

GeForce 6600 GT 256MB DDR3 TV-Out/Dual DVI (AGP)

Western Digital Caviar Special Edition 80GB 800JD SATA 8MB Cache

Crucial 1GB DDR PC3200 CAS3 (CT12864Z40B)

[Stuey]

You should check the BIOS for a fan setting. Perhaps the fans are set to not spin below a certain temperature?

[Koiju]

Is it safe for me to check that while my PCU's fan isnt working? :S

[doctorgonzo]

What brand and model PSU do you have?

[Koiju]

The PSU came with the bare bones system, its a 250W Asus, I think. I'm already awear that 250W may be a bit low, but I wouldnt think itd cut the power to the fans, surely to the power hungry graphics card first?

Anyway, Ive briefly flicked through the BIOS (with a mains power fan pointed directly at my open PC case, heh) I saw some possabilities, not sure what it all ment. The most obvious one was an option called 'Smart fan control' would that be resposable for turning the fans off if its not hot yet?

Oh, I also saw somthing a bit odd, on the same page, it had options for telling it the fan speeds, both were set to N/A :S

[doctorgonzo]

The case fan isn't connected to the motherboard, is it?

[Koiju]

LoL, yes, the case fan and CPU fan have both been plugged into there respective mobo slots. (they wouldnt come on at all if I haddnt I would have thought :S)

Oh, and I tryed dissconnecting the case fan from the mobo, just to see if the CPU fan would work by itself. It did the same thing, on then off.

[doctorgonzo]

It is it under warranty, I'd contact them about it. It could be a bad motherboard.

[Koiju]

I uh, dont know :S Ive gone to the ASUS site, am looking for some kind of support thingy there.

But while im doing that, what about what was said about the fans auto turning off? Is that to do with the Smart fan control thingy? Or shouldnt they ever turn off?

[Stuey]

Generally there are options to throttle down the fans to provide for quieter operation. If the fan speeds say N/A it means that for some reasons the fans aren't enabled. If the fans were enabled, the fan speeds should be 0 if they're not moving.

The fact that the mobo is reporting N/A for the fans suggests that a setting needs to be adjusted, or that the motherboard isn't detecting the fans for whatever reason.

[doctorgonzo]

Smart fan does control fan speed, but the CPU fan should never be completely off. Also, if the board can't read the fan speed (the whole N/A/ thing), the default should be that they are on, not that they are off.

[Koiju]

Arg, why can it never be simple >.>

Seems only ASUS will know the answer, hopfully they'll reply quickly.

Thanks for all your help though