MacBook Duo fan speed and problems

WIfe was working on her Macbook Duo, when it made a noise and then the fan seemed to stop working. Normally, she could cause the fan to run pretty loudly as she Netflixed, played video or Flash games. After that noise, the fan no longer ran that loud or fast.

I installed Fan Control and it said the left fan was fine, running at various speeds, while the right fan was -1 RPM.

Ok, didn't know a Macbook had two fans, but I ordered the only one that was available for my model on iFixit and installed it.

Same problem. Fan control says the right fan is moving at -1 RPM. There is no loud fan noise, even when doing activities that use to cause the fan to spin loudly.

The computer works fine, but the temperature on the CPU and Airport card climbs after a while (according to iStat Pro). The RPM of the (one?) remaining fan steadily climbs, but doesn't seem to go over 2500.

So what's the deal, anyone? I replaced the fan, yet I can't verify that it's running. I don't know what to do next or even if there's a problem