3-Pin Fan Header Pin Order

[Jeff DeMaagd]

Chris Meadors wrote:
> I wired the new fan as:
> 
> 1 Positive
> 2 RPM sensor
> 3 Ground
> 
> When I power up my machine the fans are spinning, but the LCD display
> says fan failed during the self test.  As soon as it gets to starting
> CPU 1, it powers the machine off.
> 
> Two questions.  Do I have the wires in the right order?  (I'd think so,
> else the fan wouldn't be spinning).  Can a fan be too fast, or are the
> Alphas real picky about the RPM signal?


I think you might just have the wrong pin order.  I think it might be 
possible that you have the RPM sensor and a power lead swapped.  It 
really depends on how the fan's internal circuitry is wired, but the fan 
_might_ still spin if it were grounded or powered through the sensor 
lead.  I've seen stuff like that happen before.

Jeff