TCL LED28B2500 - Trouble shooting; Cannot Switch On

1、 Can not switch on：
i
NO
yes
Only 3.3V
Y
N
Y
Check crystal frequence
Check IIC bus
Check the peripheral circuit
of mail IC,check solder of
main IC,check data fo NVM
and reset it
Check reset
signal of main
no switch on
Check 3.3V/12V/24V of power supply
Check PW
Check DC-DC
part,check
Check signal P—ON，
DIMBL—ON of main IC link
to PW
Trouble shooting