cpu fan

[wombil]

hey guys,
I have an athlon 1.8 ghz socket A processor and the fan is very noisy so I am replacing it.The fan that is on it is just held on with screws down between the fins of the heatsink and it looks like this unit was supplied without a fan and this one is an home add on.I will still put another fan back on but my question is; "which direction should the fan be blowing?" The one on now is blowing down on to the heatsink but would it be better to have it blowing away from the heatsink and sucking the air up through the fins.
The new fan I have is a 2 pin connector,Can I hook this up to a 3 pin connector? Otherwise I can connect it to a spare molex connector.
Thanks fellers,
wombil.

[mjc]

Well...the second question first...does your motherboard monitor fan speed? If so, then, unless you can disable it, you need a different fan. There is very good chance that without the third wire, it won't boot. This is not a flaw. It is by design, to prevent a machine with a failed fan from booting and turning the processor extra crispy. CPUs of that era were especially sensitive to overheating and frying...

Direction...there are proponents of both...but if the unit was providing adequate cooling just face the replacement fan in the same direction as the original.

[wombil]

Thanks MJC,I'll start looking for a 60mm fan with 3 pins.It just looked to me as tho the original setup did not have a fan,just the heatsink.I can't see any provision for securing a fan to the heatsink.The way it is secured now with 2 screws in between the fins does not look like a manufactured item.The board is a MSI KM4m.I thought that by connecting the fan to a molex connector it would just go all the time as it does now.
Anyway ,thanks again,
wombil.

[mjc]

It may or may not have the 'no fan/no boot'...it is from right around the time that was becoming a common feature though. And it isn't a matter of the fan not running, it is a matter of the BIOS not being able to detect the fan. If it can't sense the speed it stops POST with a 'fatal' error and shuts down. Some BIOSs allowed you to change or disable the speed setting/fan detection others did not.

[pangea33]

It just looked to me as tho the original setup did not have a fan,just the heatsink.I can't see any provision for securing a fan to the heatsink.

I also have a socket-A machine that I needed to replace the heatsink on. What you need to keep in mind is that the heatsink and cooling fan oftentimes are sold as a complete set. I got a Thermaltake that I can't seem to find online at this point, that had a metal clip that attached to two plastic tabs on the actual cpu socket on my motherboard.

As long as you buy them as a set, you don't need to worry about how the fan attaches to the heatsink, you can simply rest assured that they will indeed attach to each other in some way that the manufacturer has chosen.

The 3-pin connector serves two purposes. One is to give feedback to your bios if supported, which will allow diagnostic software to see how fast the fan is spinning. The second is to allow that software to adjust the speed of the fan in order to keep your cpu at it's target temperature.

The Thermaltake I got has a second option that allowed me to connect an included potentiometer (knob) to continuously adjust the fan speed wherever I wanted. I basically just cranked the fan up and then didn't worry about it.

As far as noise is concerned, are you talking about metal-on-metal bearing noise, or are you just talking about a loud-a*s fan? My fan spins at something like 2-3k rpm and it makes a decent amount of racket. If that's the problem, your case may be the place to look in order to solve it.

http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2000110574%201371026036&name=Socket%20A
http://www.newegg.com/Product/Product.aspx?Item=N82E16835106607

[wombil]

Thanks for the advice fellers.This fan makes more noise than my 30 year old diesel truck,so I reckon it's pretty well clapped out.I'll just look around for a proper fan.
wombil

[wombil]

OK Guys,
The only 3 wire fan I can get hold of is a 50 mm fan [I'm thinking a new 50 is as good as an old 60?}
Would there be any risk of installing this fan with the addition of a 120 mm case fan that I have?