Slightly off topic but has anyone else had issues with the fingerprint reader? Sure it's nice but if it takes like 1-3 minutes to get it to actually read your fingerprint properly and to boot the machine..oh well. Occasionally it works just fine but most of the time you have to swipe your finger over and over again to get that green light. And yes, I do know how to use it. It's just not very reliable.
The fingerprint reader on my X220 is very reliable, the best such device I've ever used.
Try enrolling your fingerprint over again. If that doesn't help, contact Support for a warranty replacement.
Hope that helps, John ThinkPad T450s [ i7-5600U | 8GB | 1TB SSD | Full HD IPS | 802.11ac | BT | Webcam | FR | Win8.1Pro64 ]
The fingerprint reader on my X220 works very well for me too. As suggested, try enrolling your fingerprint again, and for more than one finger. If it still doesn't work well, it should be handled through warranty.
The fingerprint reader almost always works for me on the first swipe. I use it 8-12 times daily and I often go for 2-3 days without having to swipe more than once.