Thinkpads Forum

When working on my X201 I found that the antennae - particular on the full-height PCI "WAN" card (which presumably I never use anyways) - seem to be backwards. The MAIN connector on it has a red arrow, but the antenna cable with blue tubing on it connects to it. Similarly the AUX connector has a blue arrow but the cable with red tubing goes to it.

The intel WiFi (mini) card might make slightly more sense; the one with grey tubing on it goes to MAIN and the one with no tubing to AUX; although there are no colored arrows on that card.

I did buy this laptop used (on ebay) and it works fine (aside from the fan that I am replacing). I noticed that these two cards are each also held in by only one screw each (the HMM states they should each have two) so there is a fair chance that someone did something with them before.

Someone swapped the WAN leads.
On a 3-wire card, grey goes to left, white (if you have it) in the middle and black to right.
If you don't need/use WWAN, put the red one in the middle of wifi, if you only have 2 antenna wires.