Multi F Four-Way Ceiling Cassette Service Manual
Part 5. Trouble Shooting 
- 75 -
Copyright ©2014 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
Display
code
Title Cause of error Check point & Normal condition
67 Fan Lock Error
Fan RPM is 10RPM or less
for 5 sec. when ODU fan
starts or 40 RPM or less
after fan starting.
• ODU fan locking
• Heatsink assembly of INV PCB assemble condi-
tion abnormal
• Defect of temperature sensing circuit part defect
of INV PCB
 Is ODU Fan Motor Assemble 
condition normal?
No 
Yes 
Recheck power and installation condition
Check ODU Fan Motor assemble condition and fan locking
-> Reassemble or replace if abnormality found
Is ODU Fan Motor normal?
No 
Yes 
1. Set the multi tester to diode mode.
2. Check voltage between 1pin and 4pin of Fan Motor
 (1Ţ0.2V)
3. Replace Inverter PCB if abnormality found.
Is wire connection of 
ODU Fan Motor wire normal?
No 
Yes 
Check wiring between OUD fan motor and Inverter PCB
( Check if Hall Senor and Motor output terminal color is 
matched)
-> Reassemble if abnormality found
Is connector PCB assembly normal?
No 
Yes 
Replace connector PCB assembly
Yes 
Is main PCB assembly normal?
No 
Replace main PCB assembly
■ Error Diagnosis and Countermeasure Flow Chart
Check Point
1. Check voltage between 1pin and 4pin of Fan Mortor connector (Tester diode mode)
2. Voltage value should be in 1V ±0.2V. 










