I just had this problem so I thought I would post my experience.
I've had my KT for about a month and charged it for the second time (other than out-of-the-box) from a wall charger.
I plugged it in last night when I went to bed and unplugged it at about 4:00 am. When I tried to turn it on this morning, I saw a brief blue light (much shorter than normal) and then nothing. I tried plugging in the charger again and the green light came back on but the reader didn't wake up. Remembering that this thread existed I thought I'd check what others had done before resorting to a pin reset.
- Tried connecting the KT to my laptop. Green light but no action.
- Tried a different USB port. Same as above.
- Thought that trying a different cable sounded like a good idea but I couldn't find one so I made coffee instead. When I got back to my laptop my KT was alive!
What's different from other postings here is that the reader wasn't charged, although it's charging now.
In summary, it appears that the solution is to plug the KT into a computer and go make a pot of coffee.
