The "XX" is a different error message depending on the condition of your machine.
Unplug the machine from the power for several minutes, and then reconnect it.
If your machine has FAX functions:
If you cannot print received faxes, transfer them to another fax machine or to your computer before unplug the machine so you will not lose any important messages.
Then, unplug the machine from the power for several minutes and reconnect it.
