CPU-fan issue

A friend purchased a P35-DS3P mobo with two sticks of 1gb DDR2 RAM, a 3-pin
Coolermaster HSF, and a PCI-E video card to upgrade an older P4 478 system
in an ATX case. The PSU is a 480W Antec Truepower, and when everything is
connected the only response is a quick flicker of the CPU fan--no POST, no
PSU or case fans are spinning up, nothing. OTOH, when the CPU fan connector
(3-pin on the HSF, 4-pin on the mobo) is moved to a case-fan connector on
the mobo, it boots with no problem.

While this was connected, I connected the original Intel HSF (4-pin) to the
mobo's CPU-fan connector and although it still started fine the HSF
connected to the CPU-fan mobo connector (not attached to the CPU) would only
blip on every few seconds, never fully cranking up. I tried the same test
with an old 478 P4 HSF with a 3-pin connector and it would blip once, then
nothing. IOW, none of three HSF's (two 3-pin, one 4-pin) will work on the
mobo's CPU-fan connector.
We returned the first mobo thinking it was a mobo issue, presumably a bad
CPU-fan connector, but this second mobo is no different.
The 3-pin connector fits only one way with the guide on the mobo,
so I assumed the 3-pin-connector HSF's would work.

At this time it appears to function fine as long as the HSF is connected to
a case-fan connector on the mobo, but these seems make-shift to me. What am
I missing on this 4-pin CPU-fan connenctor issue?

Bob Davis wrote:
> A friend purchased a P35-DS3P mobo with two sticks of 1gb DDR2 RAM, a
> 3-pin Coolermaster HSF, and a PCI-E video card to upgrade an older P4
> 478 system in an ATX case. The PSU is a 480W Antec Truepower, and
> when everything is connected the only response is a quick flicker of
> the CPU fan--no POST, no PSU or case fans are spinning up, nothing. OTOH,
> when the CPU fan connector (3-pin on the HSF, 4-pin on the
> mobo) is moved to a case-fan connector on the mobo, it boots with no
> problem.
> While this was connected, I connected the original Intel HSF (4-pin)
> to the mobo's CPU-fan connector and although it still started fine
> the HSF connected to the CPU-fan mobo connector (not attached to the
> CPU) would only blip on every few seconds, never fully cranking up. I
> tried the same test with an old 478 P4 HSF with a 3-pin connector
> and it would blip once, then nothing. IOW, none of three HSF's (two
> 3-pin, one 4-pin) will work on the mobo's CPU-fan connector.
> We returned the first mobo thinking it was a mobo issue, presumably a
> bad CPU-fan connector, but this second mobo is no different.
> The 3-pin connector fits only one way with the guide on the mobo,
> so I assumed the 3-pin-connector HSF's would work.
>
> At this time it appears to function fine as long as the HSF is
> connected to a case-fan connector on the mobo, but these seems
> make-shift to me. What am I missing on this 4-pin CPU-fan connenctor
> issue?

If its anything like the GA-P35C-DS3R I did for someone a while ago, you
might want to go into the BIOS and have a fiddle with the settings - it had
some odd default ones.

I also returned the board only to get the same problem on the new one.

As it happens the problem I initallly had was the same as yours, the CPU fan
flicked around a small bit and then nothing. It turned out it was the
memory. Read my answer to the post 'new build - no display on monitor' on
this group yesterday.

SteveH