Mitsubishi Heavy Industries FDT90VNPWVH Service Manual page 77

Error code
INSPECT I/U
Remote control:
1. Applicable model
All models
2. Error detection method
Indoor unit cannot communicate
for more than 30 minutes after
the power on with remote
control.
3. Condition of Error displayed
Same as above
4. Presumable cause
• Improper setting
• Surrounding environment
• Defective remote control
communication circuit
• Faulty indoor unit control or
power PCB
• Faulty outdoor unit PCB
Note:
If any error is detected 30 minutes after displaying "
"INSPECT I/U".
LED Green Red
Keeps flashing Stays OFF
Indoor
5. Troubleshooting
Diagnosis
Are more than
3 units of remote control
connected?
NO
Does remote
control display
"Slave"?
NO
Do more than
one indoor units have the
same address?
NO
Is it set to
a slave indoor unit.
SW5-1, 2?
NO
Is there loose
or wrong connection at the termanal
of wiring between indoor and
outdoor units?
NO
Is the
grounding wire connected
properly?
YES
Is approx.
DC20V detected between 2/N -
on the outdoor unit terminal
block?
YES
Is approx.
DC20V detected between -
on the indoor unit terminal
block?
YES
WAIT
76
-
Content
INSPECT I/U
(Connection of 3 units or more remote controls)
YES
YES
YES
YES
YES
NO
NO
NO
" on the remote control, the display changes to
-
'19 • PAC-SM-334
Countermeasure
Reduce to 2 units or less.
Change remote control
setting to "Master". (SW1
on remote control PCB)
Change address. (SW2 on
indoor unit control PCB)
Change to master. (SW5-
1, 2 on indoor unit control
PCB)
Correct.
Correct.
Defective outdoor unit
PCB➞Replace.
Broken connecting wire➞
Correct.
Defective indoor unit
control or power
PCB➞Replace.