Mitsubishi Electric PU(H)Y-P250YGM-A Service Handbook page 139

[ IX Troubleshooting ]
Error
Error definition and error detec-
Code tion method
6602 Transmission processor hard-
ware error
Although "0" was surely trans-
mitted by the transmission pro-
cessor, "1" is displayed on the
transmission line.
Note: The address/attribute
appeared on the display
on the main remote con-
troller indicates the con-
troller where an error
occurs.
(1) When the wiring work of or the polarity of either the indoor or outdoor trans-
mission line is performed or is changed while the power is on, the transmitted
data will collide, the wave shape will be changed, and an error will be detect-
ed.
(2) Grounding fault of the transmission line
(3) The male connector is connected to the female power supply switch connec-
tor (CN40) in the system with the main controller connected.
(4) Controller failure of the source of the error
(5) When the transmission data is changed due to the noise on the transmission
line
(6) Voltage is not applied on the transmission line for centralized control
Check method and remedy
Is the transmission line work
performed while the power is on?
NO
Check the power source of the indoor unit.
Power supply voltage?
YES
Check the transmission line work is performed
and the shielded wire is treated properly.
Grounding fault or does the shielded
wire contact with the transmission line?
NO
System ?
Single-outdoor-unit system Multiple-outdoor-unit system
*For the investigation method, follow
Investigation into the
transmission line noise <Investigation method of transmission wave shape/noise>
YES
Noise exist?
NO
Controller failure of the
source of the error
- 130 -
Check method and remedy
YES
Turn off the power source of outdoor/indoor
units, and turn them on again.
NO
Faulty power source work
YES
Improper transmission line work
NO
Investigation into the
cause of the noise
System with the main remote
controller connected
Confirm that the power supply
connector on the outdoor
unit is not plugged into CN40.
Is the male power supply connector
connected to the female power supply
switch connector (CN40) ?
YES
Disconnect the male power supply
on CN40 and connect it to CN41
Correct the error.