What does the “Power Reset” message mean?

This indicates that there has been an interruption to the power supply to the device.

If you are using batteries:

Ensure you are using Duracell batteries, and replace the full set when the device reaches 10% power or less. If the issue persists, try using a power supply instead. 

If you are using a power supply:

First, try a different plug socket. If this does not resolve the issue, switch to batteries. If the batteries work correctly, then test with an alternative power supply.