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White screen
Check
whether u502_D
voltage is
normal
Check
whether u502_G pin is
low level
Check
whether U15_37
(PANEL_ON) is low
level
Change MST718
Check
whether Q505_C is
high level
Check Q504 and peripheral
elements
Check Q505 and peripheral
elements
Check
whether 3.3V
voltage outputted
by U505 is
normal
Change U505
Check
whether X101 clock
is normal
Check X101/C103/C104
Check
whether drive
output pin MST718
outputs
normally
Change MST718
Check
whether the socket
and flat cable from main
board to display screen
are normal
Change flat cable or socket
Change display screen
Y
N
Y
N
Y
N
Y
N
Y
N
N
N
Y
N
Y
[ Flow chart 4 ] Symptom: white screen
Description: screen is white and indicator on
Change U502
Y
N
Check
whether 2.5V
voltage of pin 2 of
U507 is
normal
Change U507
Y