The wifi signal on my x201 dropped from full to 2-3 bars for no reason a few days ago. Even I hold my x201 3 meters away from the router and there is nothing in between, the signal is still not full. I looked at an other computer and the signal was very strong at the same position.
I tried to uninstall the wifi adapter and uninstalled the driver and reinstall again, didn't help. I also tried to took off the antenna connectors and put them back, didn't help either.