Please take out the battery and the attached cables. Wait for a few seconds and put everything back into its place. Then you can restart your terminal. Make sure you press the ON/OFF-button long enough.
You can also check if the terminal is sufficiently charged:
- 9220: a green light should be signalling at the top right of your terminal
- 8210: the indicator next to the USB connector on the left side should be signalling green or red
- 6210: the indicator next to the power button on the left side should be signalling green or red
If nothing happens at this point, please contact your terminal provider.