Canon LASER CLASS 710 - Page 273

LASER CLASS 730i/720i/710 Chapter 5: Appendix
5-65
3.6.4 Maintenance and service
a) Troubleshooting
The fax does not recognize the dual-line upgrade kit III even when it is
attached properly.
Solutions: (1) Check that the kit is securely connected.
(2) Replace the kit.
(3) Replace the SCNT board.