Mitsubishi Electric MR-385S-W-A Service Manual page 19

6.4 Malfunction Display and Checking points.
6.4.1 ) Malfunction display will use LED for show self-check
6.4.2 ) Fucntion display
Lighting mode (time amount) will blink by on 3 min. as fixed times amount after that will off 5 seconds, which will repeat as cycle sample.
1 time 2 times
ON
OFF
Cycle
6.4.3 ) Repairing and check point
* A the case below , if the analysis result has malfunction over 2 points and will express in the list has more importance.
Function display
1 time Fault trouble of freezer thermistor
2 times Fault trouble of defrost thermistor
3 times Fault trouble of defrost heater
Caution
1. Before plug in the AC power , Be ensure the comp had been off more than 20 min.
2. The consider short circuit or open circuit of thermistor , resistance of open circuit is ∞
1 time 2 times
5 Sec. 5 Sec.
Cycle
Cause Analysis result
Open circuit or short
circuit case
Open circuit or short
circuit case
Defrost unfinished
with in 2 hours
1 time 2 times
5 Sec.
Cycle
Check point
1. Check connector of control PCB CN5 ,
relay connector 6 pin
2. Check the resistance of thermistor
1. Check connector of control PCB CN5 ,
relay connector 2 pin
2. Check the resistance of thermistor
1. Check connector of control PCB CN1 ,
relay connector temp. fuse
2. Check the resistance of defrost heater
3. Check the resistance of temp. fuse
, resistance of short circuit is 0
Ω Ω
1 time 2 times
5 Sec.
Cycle
Corrective Priority Repairing
Improve in contact
1
Change part
Improve in contact
2
Change part
Improve in contact
3
Change part
Change part