FRITZ!Fon C5 Service - Knowledge base

FRITZ!Fon C5 Service

FRITZ!Fon reports "IPEI invalid!"

Registration of FRITZ!Fon fails. The error message "IPEI invalid!" is shown on the telephone's display.

1 Restoring the telephone to its factory settings

  1. Press the "Menu" key on the telephone.
  2. Scroll to "Settings" and press "OK".
  3. "Reset" > "OK" > "OK"

2 Re-registering the telephone