An Old Subject / 3pin to 4pin fan headers

[Pelltuk]

I know that this is an old subject. I have just resurrected an old PC which has got a NEC Bogota MS-7295 MB and is fitted with an AMD 2 processor. Because the fans were making so much noise I decided to replace them all with super quiet ones. The CPU & heatsink combo is a Gelid Siberian Pro and is perfectly adequate for what I require, but comes with a 4 pin connector and my MB has a 3 pin header. No problem I hear you say just leave plug over hanging, the fan will just run at full speed.
When I switched on the PC, the fan ran for about 10 seconds then stopped and the blades were just twitching slightly, after about 10 minutes of no fan activity I decided to check temp of heatsink. It was getting rather hot to the touch so I switched off.
I have got another old cpu fan with a 4 pin connector so tried that with same results, looking at connector wiring it was Black,Red, Blue then Yellow ( cant tell on new fan as all are black) Now I have always been told that the blue is the pulse line for speed control not Yellow, switching these 2 around in the connector now lets fan run at full speed so did the same swap on the black wires.
Any thoughts or comments would be gratefully received as I would rather the fan did not run at full speed all the time.

 

[soccerballtux]

many fan controllers can do both analog and PWM, check out BIOS settings to switch to analog. on mine its "Manual" that activates analog