My 8310 will boot up and the pin screen flashes for a second and then goes blank - the phone appears to be dead. If i plug in the charger the pin screen comes up again for maybe 5 or 6 seconds but my keypad and roller ball are inactive. It was working perfectly this morning, i powered it off during a meeting and now i cant turn the thing on. If i plug it into my computer I can access files on the phone via the USB cable. But I cant enter my pin to turn it on. I have taken out the battery and reset it and that made no difference. Any suggestions.

Is the device charged well?

Leave the device to charge 2-3 hours, and then, still connected to the USB cable, remove the the battery from the device a few seconds and reinsert it. If it boots--leave it to charge to 100% (check Options > Status for the percentage).

If it doesn't boot--try using a wall outlet charger if you are not. If you are connected via USB to the PC, make certain that you have Desktop Manager (or the USB device drivers) installed, which you can download below.

Make certain your USB cable is connected to one of the PC's main rear USB ports. Not a USB hub, nor a monitor USB port, nor a USB port on the front of the PC.