Dell E153FPTc Service Manual page 40

Panel Power Circuit
Check R172 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 is
Green, R172 should =5V
If PPWR no-response when the power switch
Turn on and turn off, replace the U101
NG
Check U101 pin8=5V
NG
Check the BKlt-On relative circuit,
R162, in normal operation, when LED=green,
R162 BKlt-On should=3.3V, If BKlt-On
no-response when the power switch turn
on-off, Replace U101
NG
Check NO SCREEN APPEAR block
40
DELL E153FPTc
OK