Same happens to me. I just emailed Nokia about it. This is what I wrote to Nokia: My N810 does not power on anymore. When I first got it out of the box, it only turned on after I left it on the charger for a while. I thought that would be normal, since I expected the battery to be empty. Later I tuned the device off, while I was sure that the battery indicator indicated 3 hours left. I could not turn it back on. Pressing the button for 3 seconds had no result (led also stayed dark). I connected to the charger for a few minutes and then the charging icon appeared. With the charger still connected I could turn it on. To test more, I turned it off, charged it overnight (in the off state) until the display showed the charging icon and the message to disconnect the charger to save energy. I disconnected the charger and tried to switch it on... nothing. I reconnected the charger: nothing happens, not even the charging icon in the middel of the screen appeared. The device just seems completely dead. I tried replacing the battery, removing the memory card. Nothing. I measured the voltae of the battery, which was 4.06V (between pins + and -) which seems okay. I remember havin a similar problem with my N800 in the beginning, but that was solved somehow (maybe new softare fixed it). I hope this is a known problem and that you have a solution.