Default boot priority and case fan question?

Vidya · 31 Oct 2012 at 20:07

Is the default boot priority for motherboards normally Optical Drive > Hard Drive, I know it's changable was just wondering if the default is Optical Drive > Hard Drive?

Also, I've just built a new computer and it seems like 2 of the case fans are a bit faulty, in bios their RPM readings go from 800 to 1400 to 19,640RPM, I've checked to see it is the fans and not my mobo by switching them around the fan points and I've deducted it's the fans, what would cause them to act like this? Is it broken sensors and does it matter?

They are Corsair 550D case fans

Tealc · 31 Oct 2012 at 22:13

The 19000 rpm sounds like its picking up a PWM signal from somewhere and using that instead of the hall sensor output, probably because the fan voltage is low.

Sparx · 31 Oct 2012 at 23:20

Typically I have it set to: Hard Drive > CD/DVD Drive > USB Drive > Network Drive

Vidya · 31 Oct 2012 at 23:27

Tealc said:
The 19000 rpm sounds like its picking up a PWM signal from somewhere and using that instead of the hall sensor output, probably because the fan voltage is low.

Any way to fix this? How is it picking up a A PWM?