LG ARUN Series Service Manual page 120

Troubleshooting Guide
Error No. Error Type
77*
Master 771 Fan Over Current Error
Slave 772
I Error Diagnosis and Countermeasure Flow Chart
Is installation
condition normal?
Yes
Are the resistance
Between each phase and insulation
resistance of motor output
terminal normal?
Yes
Is motor wire connection
condition normal?
Is Fan PCB assembly normal?
Yes
Recheck power and
installation condition
Copyright ©2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Output current is over 5A for 40ms
No
Check ODU fan motor assemble condition and locking
¡ Reassemble or replace if abnormality found
1.Check resistance between each motor output terminal
(refer to page 63)
No
2. Check insulation resistance between ODU fan motor terminal(U,V,W) and pipe
(over 100MΩ )
¡ Replace fan motor if abnormality found
1.Check if color of motor output terminal(U,V,W) connector matched with PCB's
No
2.Check wire disconnection and wiring
¡ Reassemble or replace if abnormality found
No
1. Check fan PCB assembly IPM normal
¡ Replace Fan PCB assembly
Measuring fan motor phase
resistance
Fan motor wire connection
- 120 -
Error Point
1.Overload operation
2.Fan Motor defect
3.Fan PCB assembly defect
Hall Sensor connection
Main Reasons
LGE Internal Use Only