Testing a fan

[2ndgencamaro]

This past weekend I took apart a laptop - T500 - which was generating a "Fan Error" message then shutting down. I did not find a lot of dirt in there but wanted to try a clean and lube before buying a replacement. Can anyone suggest a way to test the fan other than reassembling the laptop? The power button is on the keyboard so I was looking for a means to test both the old fan and the used replacement before spending an hour taking it apart once again.
Thanks.

[rkawakami]

About the only way I know of testing the fan would be:

- installing it in the system, putting it back together enough to power up the system and...
- either run a fan control utility such as TPFancontrol or if you have a copy of PC Doctor for DOS for the T500 AND it still has a Fan diagnostic, using that.

[2ndgencamaro]

Thanks for the info but I was suspecting there was no easy means to test it.

[axur-delmeria]

You'd probably need the following:

1. pin layout of the fan and its operating voltage (laptop fans usually top out at 5v)
2. variable voltage DC power supply
3. something to detect the RPM sensor pulses, like a logic probe or oscilloscope.

I haven't tried it as I don't have the equipment (esp #3), but I believe it would work.

[RealBlackStuff]

I have removed the fan-socket from a faulty motherboard, and soldered it with a potentiometer to a cut-off USB cable.
Any time I need to test a fan, just plug it in, plug the USB in a 'live' port and change speed with the pot-meter.
Works like a charm, even though this 'mod' only works for speed-control, not temp-sensors.