Midea HS-455LWEN-W1, Instruction Manual

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9.10 Self-diagnosis

Conditions for entering into this mode
When the power is on for the first time, here is no sensor failure and the defrost sensor
temperature is equal to or more than 0°C.

Self-diagnosis process
1. Defrost heater is on for 2 seconds and off for 2 seconds;
2.The fan is on for 10 seconds and off for 2 seconds;
3.The refrigerator is refrigerating for 20 minutes. (The compressor fans are all on)

Exit out of self-diagnosis
1
、
1.Stop self-diagnosing and turn into normal mode;
2.Failure occurs to the sensor during self-diagnosis and exit out of self-diagnosis mode;
3.Set forced defrosting function during self-diagnosis.
10.Circuit description
10.1 Power Supply
The AC input power is reduced in voltage by SMPS control chip and filtered off wave by the
inductance-capacitance filter, then output the DC 12V power which will mainly power the relay
that controls strong current. Relay is used to control the strong current loaded switches of
compressor, ice maker and defrost heater. The DC 12V power will output stable 5V electricity
after passing through the adjustor 7805, to power for the main control chip and thus monitor the
temperature changes in refrigerator.