KH>Jasen Betts wrote to Ken Hrynchuk on 02-09-03 23:08:
 
KH> KH> My new BIOS has CPU fan monitoring available, but I didn't get the
KH> KH> adaptive cable with the MB, so I'd like to make one, if possible.
KH> KH> First, does a 2-wire CPU fan support monitoring, or would I need a
KH> KH> 3-wire type?
 
KH> JB> you need three, many 2 wire fans have three terminals internally -
KH> JB> you could add the missing wire.
 
KH>I tried getting the fan off to check, but it's stuck fast to the CPU,
KH>even after spreading the (flimsy) plastic retainer clips. The fan and
KH>CPU are both Intel, so I guess it's one of those 'retail' Fan/CPU
KH>packages. Is it normal for the fan to be stuck like that?

Not in my experience. Possibly overheated and now
"welded"????

Jay
 
KH> KH> The MB has a 3-pin fan monitoring connector -12v +12v
KH> KH> -12v; am I correct in assuming that I'd run 2 wires in series
KH> KH> after the fan to the appropriate pins (if 2-wire is supported), or
KH> KH> would I need some other components?
 
KH> JB> extra components would be needed to get a rate signal from a 2 wire
KH> JB> fan.
 
KH> JB> it's easist to tap the monitioring terminsl on the fan PCB.
KH> JB> (typically right next to the power terminals)
 
KH>There's nothing like that visible, just the two factory terminals; or,
KH>did you mean inside the fan assembly?

See my msg to Roy T.
 
KH> JB> +12 / -12  doe that been 24V measured between the pins ?
 
KH> JB> I'd expext one of the pins to connect directly to the mootherboard
KH> JB> ground (that'd be 0v) the other win will have about 12V on it when
KH> JB> powered up, the third one will be the "fan rate" terminal
 
KH> JB> and would probably measure a moderate resistance to the Ov pin
 
KH>Thanks, Jasen; I've saved the information, for future references.
 
Jay
---
 þ OLXWin 1.00b þ Keep that soda away from the keyboooooooooooooooooooooooo