• Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
    Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.

A (probably) dumb fan question

S

starhawk

[H]F Junkie
Joined
Oct 4, 2004
Messages
8,908
Hey, if it wasn't 10pm here I'd be bothering my local tech dude over this. It's late so I'm bothering you guys instead :D

Got a mobo here from a compaq, bought it used here on [H], it's a 939 board, an A8AE-LE. Kinda an odd quirk just popped up, and I'm wondering where I should place blame before shrugging and moving on.

The CPU HSF is a ThermalTake Volcano somethingorother. (I forget the exact model.) The fan on the 'sink was a ThermalTake (!) TT-7025A, vintage '03. This fan says it pulls 0.4A of current.

I powered the board on, and after passing POST and going through its inventorying of itself and its attachments (drives, chip, memory, etc.) it pipes up with "your CPU fan is bad and I'm turning off now SO THERE MOFO WHATCHA GONNA DO" -- or something very much like that :p

Of course I can see the fan sitting there spinning.

I replace it with a fan off a cooler master heatsink, dunno the model number, something long and fairly anonymous. This fan has a 0.3A rating, and the board boots my testing OS just fine (this mobo's been through a bit, so I'm just trying to make it run at this point).

So the question is... was the ThermalTake fan just pulling too much current for the board to handle, or was it actually in the process of failing and I just couldn't see it?
 
Could be pulling too much current, your troubleshoot would be to use a different .4A fan and see if it produces the same result.
 
Not digging through my fan bin right now... most of my stuff is 80mm anyways -- won't fit, this is a 70mm HSF.
 
Depends on how it gets the signal. It might be looking at the third pin on the fan connector, which sends an RPM signal. If the fan is not sending out the RPM signal, the mobo will think the fan isn't spinning.

I doubt it's measuring the current of the fan, and if it was, you said it yourself - the original fan was pulling more current than the replacement. It's gotta be looking at the RPM signal, and the original fan must not have been sending it.
 
starhawk said:
OK, so how do I test the RPM lead? I don't have an oscilloscope...
Click to expand...

You could always try a different fan on that header and going into the BIOS to see if it picks up an RPM signal, and/or try that fan on a header on a mobo in another computter and see if that BIOS displays a RPM, but that's just going to tell you where the failure is. If the fan seems to be working, just disable the fan warning in the BIOS and move on.
 
try pulling the battery to fully reset the BIOS just in case it is giving a false positive. I always ran my aftermarket HSF's with pass-throughs like this:

http://www.performance-pcs.com/catalog/index.php?main_page=product_info&cPath=34_82&products_id=284

because I used the Delta screamers way back and didn't trust the headers on older boards.

Anyway if reseting the BIOS doesn't clear the warning look to turn the warning off as nalc said, if it doesn't have a disable, use the other fan that does work and zip tie that sucker, or mount it and swap the leads so the extra fan is running off the cpu header.

Just make sure it is actually spinning and cooling good because the older CPUs didn't have good thermal protection and can fry, that is why the bios is complaining and turning the PC off.

( also reminds me that I have a old swifttech 80mm HSF and delta fan I bet I could mod for something in my parts bin... :)
 
You must log in or register to reply here.
Back
Top