Canon FAX L1000 Service Manual page 557

c) Communication problems
• D-channel connection error (Service error code "##1001~##1131")
(1) Set #4B ISDN BASIC Bitswitch SW03 bit2 to "1".
(2) Set #4B ISDN BASIC Bitswitch SW03 bit4 to "1".
(3) Set #4B ISDN BASIC Bitswitch SW03 bit5 to "0".
(4) Set #4B ISDN BASIC Bitswitch SW08 bit2 to "0".
(5) Set #4B ISDN BASIC Bitswitch SW01 bit4 to "1" and #4B ISDN BASIC Numeric
No.19 to "3".
(6) Set #4B ISDN BASIC Bitswitch SW06 bit0 to "1".
• Cannot perform G4 communication (After a G4 call, fall back to G3.
G3 communication will complete normally.)
(1) Confirm whether or not the receiving side is using G4FAX.
(2) Set #4B ISDN BASIC Bitswitch SW03 bit2 to "1".
(3) Set #4B ISDN BASIC Bitswitch SW03 bit4 to "1".
• Cannot perform communication
(1) Check that the ISDN cable is securely connected.
(2) Check that the kit is securely connected.
(3) Replace the kit.
(4) Replace the TWINS board.
(5) Replace the SCNT board.
FAX-L1000 Chapter 5: Appendix
5-199