Four wire fan to three wire?

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Here's the situation:

I was given a HP s3027c Pavilion Slimline desktop:

which the previous owner told me kept "shutting off unexpectedly". After
working on the computer for a short time, it quickly became apparent
that the culprit was an overheating problem. I tried every trick in the
book, replacing the thermal paste, checking BIOS settings, etc. etc. but
nothing worked until I replaced the four-wire heat sink fan with an
"always on" three-wire fan. Doing that lowered the CPU's operating
temperature in each core by about 40 degrees C. That was the end of the
overheating problem.

However, the fan I used is a cheap one which isn't that well balanced,
and the computer continually vibrates slightly. I don't like the
implications of that as far as overall computer life. I do have a good
AMD four-wire heat sink fan though, so can anybody tell me if it's
possible to cut the pulse-width modulation wire on a four-wire heat sink
fan and have it basically turn into a three-wire fan that runs all the time?

Please don't try to divert the topic by discussing the merits of
three-wire vs four-wire fans. I'm only looking for an answer to this


John Corliss

Re: Four wire fan to three wire?

On 8/23/2010 2:22 PM, John Corliss wrote:
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I have not tried it but in theory it should work with no change. In other
words the PWM pin is not needed and without it the fan should run at full
speed (or at whatever speed the supply voltage allows it to move).

Take a look at:

Re: Four wire fan to three wire?

John McGaw wrote:
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A most excellent reference! Many thanks! Bookmarked and now I will give
it a try as soon as I am able!

John Corliss

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