Bizarre CPU Problem

[jinitiator]

Hi, since replacing my heatsink and fan (from stock to a low noise/rpm model), my computer beeps at me incessently when I boot it up. It's a high-low repeating sound from the mobo speaker. Basically, the bios doesn't recognise the CPU fan is spinning (even though it is), and just reads 0 RPM. I have to run Prime95 for about 10 minutes after booting up to get the CPU hot enough for the fan to rev to 700RPM, at which point the computer seems to recognise it and stops beeping. The PC always boots fine and the CPU always remains a perfectly reasonable temperature, even when I'm being beeped at....most annoying.

I can't go back to the stock cooler as I broke the bracket when I removed it (doh!), so for now I've resorted to stuffing blu-tac in the mobo speaker to deaden the sound a bit, but it's still really loud. I'm open to suggestions! I could use some help before it drives me nuts and I rip the speaker off the mobo (and inevitably break the whole thing knowing my luck).

The system is a P4 2.4 northwood, amibios, microstar 645e max2 motherboard. I have upgraded all bios and drivers to the latest versions, and there appears to be no options in the bios to disable warning sounds etc, or anything I could use to shut the damn thing up. Any ideas?

 

[BoboKatt]

IF I am not mistaken, some aftermarket HS/f combos do not have the standard 4 pin connections to the mobo which might not allow the board to read the speeds correctly. I know in my older 939 mobo heck my CPU fan would not even spin up for a good 5 minutes after starting my computer. The bios had this setting which turned on the CPU fan ONLY after the CPU reached a certain temp. The thing was I could not lower this setting to anything LOWER than 25c and my CPU would rate on the board at 20c when it started and would not reach that temp for a good bit.

Anyhow not your issue but I guess if you are not given ANY choice in the BIOS to change when or how the CPU fan will spin, at what speed ect.. the only thing, as long as you know for sure the fan is running and your CPU is running properly cooled is to just unplug the stupid PC speaker from the board. I never bother plugging that darn thing in anyway.

 

[Viper GTS]

You should be able to find an option in the BIOS to disable the alarm (or reduce the minimum RPM threshold to levels that will work with your new fan)

Worst case as BoboKatt mentioned you can unplug the speaker, or feed the sensor an RPM wire from another case fan.

Viper GTS

 

[jinitiator]

Ah yes, how would I stop the speaker though? it's just a beeping thing attached directly to the mobo, it doesn't actually have any wires coming out of/into it (it's like one of those really lame speakers you get inside cheap musical birthday cards, about the diameter of a nickel), and as it was a store bought pc originally it doesn't have a lot of bios options :\

 

[Quiksilver]

Buy a new stock bracket off ebay and replace the heatsink back to stock.

 

[Viper GTS]

Originally posted by: QuiksilverX1
Buy a new stock bracket off ebay and replace the heatsink back to stock.

That has to be the worst possible option.

Is the fan noise on the new fan tolerable at the higher speed? It might be simpler to just run the fan directly off of your power supply so that it runs at a constant speed, and then feed the RPM output to the motherboard. The motherboard doesn't actually need to power the fan, it just needs to know that its spinning. If your fan speed changes under load your motherboard is attempting to control the fan but providing insufficient voltage to keep the RPMs over the alarm threshold.

This adapter would work nicely:

http://www.petrastechshop.com/3pinto4pinad1.html

If it's too noisy at 12V you could move the pins to get 7V instead.

Viper GTS

 

[KingTech]

I am also get confused because there are two solutions for it. One is to disable speaker from BIOS and other is replacing entire fan. What is the right solution?

 

[BadRobot]

I vote for ripping the speaker off.
It has a high chance of ruining the mobo but breaking something has a 90% chance of making me feel better when it is pissing me off.

 

[Kirby64]

Solution 3(best solution): Disable the low RPM speed alarm in bios.

 

[jinitiator]

There is no option to do that :|