If your Archos MP3 player is powering off for no apparent reason, the problem most likely is a dead or dying battery. Replacing the battery will require disassembly of the unit, but you can do it yourself without the help of a service technician. The best part is that it only takes a few minutes.
Turn off your Archos and turn the unit over.
Remove the two screws on the corners of the side of the rear of the unit and set the screws aside.
Remove the back panel to expose the rectangular battery inside.
Lift the battery out and unplug the battery cable from its port on the main circuit board. Set the old battery aside.
Fit a new battery in the old one's place and plug the cable into the port.
Replace the back panel and screws.