The Cortelco Phone is DISCONTINUED! Good-bye, old friend!
Yes, there is.
The reboot will erase phone memory. Time, date and all phonebook entries must be re-entered
Reset Instructions for 2720
1. Disconnect power adapter then tel wall jack cord
2. Press and hold DELETE and Down Arrow keys simultaneously
3. Connect power adapter
4. Wait until screen shows software version (Begins with “Ver.”)
5. Release DELETE and Down Arrow keys
6. The screen will display: SELF TEST MODE
7. Press MENU/OPTION key
8. The screen will display: EEPROM R/W TEST
9. Wait until the screen displays: EEPROM TEST PASS and then SELF TEST MODE
10. Disconnect power adapter
11. Wait at least 5 seconds
12. Connect power adapter, then tel wall jack cord.