T43 motherboard problem

[hoodie]

Machine configuration:

T43 2668-44U
Intel Petium M 1.68G
ATI Radeon X300
FRU Fan Long M24

I accidently broke the connector on the fan, when I tried to fix the noise problem with the fan. Since it is really difficult to get such a connector, I connect the fan to an external power source when waiting for the delivery of the new fan.
Trying to decide the working voltage of the fan, obviously I got the fuse F4 blown (confirmed by a multimeter).
The new fan works fine with the external power, but does not on the MBoard.
By bypassing the fuse (with the Amps function of a multimeter), the fan runs perfectly, but the 'Fan error' message persists.

I suspect this is because the motherboard cannot get the correct fan signal, but I am not sure and I've no idea about fixing this.

Any idea?

Thanks so much.

[sjthinkpader]

Yes, one of the three wires is a tachometer signal.