If you need to downgrade the unit or it does not start you can do a "Firmware restore".
- Power of the unit.
- Hold the MENU button while power the unit on…keep holding the MENU button. System recovery appears.
- Choose option 3 to restore firmware (You will lose all settings so remember to have all the configuration information written down.)
Now the unit is back to factory defaults with the firmware version in the recovery partition.
You can now configure the Konftel 300IP or Konftel 300IPx as normal and upgrade it to the latest firmware again.