YASKAWA DX100 Maintenance Manual page 344

Alarm Alarm Name Sub
Number Code
4
Meaning Cause
The communication error (loop Connection failure
back error) occurred in the EAXA
board of rotary switch was set to
"3".
YSU unit failure
EAXA board failure
Remedy
(1)Turn the power OFF then back ON.
(2)If the alarm occurs again, check the connection of the following
communication cables.
· The communication cable between EAXA board (CN518 connector) and
YSU unit (CN202 connector)
(3)After confirmation of the communication cable connection, and then if the
alarm occurred again, replace the communication cable below.
· The communication cable between EAXA board (CN518 connector) and
YSU unit (CN202 connector)
(1)Turn the power OFF then back ON.
(2)After replacement the communication cable, and then if the alarm
occurred again, replace the YSU unit. Save the CMOS.BIN before replace
the YSU unit to be safe.
(1)Turn the power OFF then back ON.
(2)After replacement the YSU unit, and then if the alarm occurred again,
replace the EAXA board. Save the CMOS.BIN before replace the EAXA
board to be safe.