Haier MT5311, Manual

Page: 79 / 92

Check if the pin No.1 of CNA1 is 5VSB
Y
N
1. Power Supply Trouble
Change the power board
Y
N
Check if the pin No.2 of UP2
is 3.3VSB
Check if the pin No.7 and No.8 of CNA1
is 5V, and if No.10 is 12V
Y
N
Check the
circuit of
UP2
Y
N
Check if the 1.2V
control circuit of
UP8 is 1.2V
Check if the voltage
on No.2 of CNA1 is
high level
Y
N
UP2
Check the power
control circuit of
QP1
Check if the pin No.3 of
UP8 is PWM signal
Check the voltage
of UP4/3/3V,UD4/1.5V
Y N
N
QP1
Check if L5/47 H is
welded of damaged.
Y N
UP8(RT8250)
is damaged
Change
damaged
O
The power
modules is
N
Y
Change
UP8(RT8250)
Change
UP8
Change or
weld L5.
Y N
circuit LDO
OK
OK
OK
trouble-shooting
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