Panel Power Circuit
Check R171 should have response from
0V to 5V when we switch the power
switch from on to off
Measured the Q104 pin 3= 5V?
OK
Inverter Control Relative Circuit
Measured the inverter connector CN104
Pin1 on/off control=3.3V (on)
Pin2 PWM signal control dim 0V-5V
Replace Inverter board to new-one
And check the screen is normal?
OK
NG, still no screen
OK
Check the PPWR panel power relative circuit,
NG
Q105, Q104 In normal operation,
when LED =green, R171 should =5V
If PPWR no-response when the power switch
Turn on and turn off, replace the U102
NG
Check U102 pin30
Check the BKlt-On relative circuit,
NG
R162, in normal operation, when LED=green,
R162 BKlt-On should=3.3V, If BKlt-On
no-reponse when the power switch turn
on-off, Replace U102
NG
Check NO SCREEN APPEAR block
38
Dell E193FPc
OK