It seemed that they were getting harder and harder to turn on. I had to press the start button on the first one longer each time to get it to start. The day it died I could not get it to turn on, and took it back to att. When I got there, it was on the boot-up att screen, and wouldn't even turn off. It got very hot.
The second one just didn't turn on one day. Took it back to att and they couldn't get it to start up either. I have two other laptops and use two different plugs for charging, one in the bedroom and one in the living room. I have never had a problem with either of them.
As I am describing this, it sounds like it was a bad connection with the start button on both. They both seemed to charge normally and at the same rate.