Haier HLE20BB Service Manual page 27

2.Display Trouble
2.1 Black
N
Tunn on or not
N
Turn on
Check U25/SM5964 PIN43
1,power supply
2,Reset
3,Crystal
Check 5V for BLON on CN7
Y
N
Check Mcu
Black Screen
N
Check the power supply
Y
Check the cirture for
Q4/MMBT3904
12V inverter input ?
Check the inverter
or self-proofed
Y