Self-Diagnosis And Countermeasures Depending On The Check Code Displayed - Mitsubishi City Multi PURY-P400 Service Handbook

[3] Self-diagnosis and Countermeasures Depending on the Check Code Displayed

(1) Mechanical
Checking code Meaning, detecting method
0403 Serial Serial transmission cannot be es-
transmission tablished between the MAIN and
abnormality INV boards.
Cause
1) Wiring is defective.
2) Switches are set incorrectly on the
INV board.
3) A fuse (F01) on the INV board has
been blown.
4) The circuit board is defective.
–105–
Checking method & Countermeasure
Check the connections, contact at the
connectors, and for broken wires in the
following wiring:
CNRS2 - CNRS3
CNAC2 - TB1B
SW1-4 on the INV board should be
OFF.
Find out if the fuse is blown, (if the re-
sistance between the both ends of fuse
is ∞), replace the fuse.
If none of the items in 1) to 3) is appli-
cable, and if the trouble reappears even
after the power is switched on again,
replace the circuit board according to
the following procedures (When replac-
ing the circuit board, be sure to con-
nect all the connectors, ground wires,
etc. securely).
1 If serial transmission is restored af-
ter only the INV board is replaced,
then the INV board is defective.
2 If serial transmission is not restored,
reinstall the INV board and replace
the MAIN board. If serial transmis-
sion is restored, the MAIN board is
defective.
3 If serial transmission is not restored
by peforming both procedures 1
and 2 above, replace both boards.