IBM ThinkPad X30, ThinkPad X31 (MT 2672 Manual page 86

Removing and replacing a FRU
Antenna cables 4a and 4b in the following illustration
are for the wireless LAN feature, and 5 is for the modem
feature.
Note: When unplugging the antenna jack, do not pull the
cable; it might snap. Unplug the jack by pulling a
tab with your fingers.
82
ThinkPad X30, X31 (MT 2672/2673)
2
4a
5
3
2
4b