Dell E152FPc, Service Manual

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DELL E152FPc
30
2.PANEL-POWER CIRCUIT
3. INVERTER CONTROL RELATIVE CIRCUIT
Check FB401 should have response from 0V to 3.3V
When we switch the power switch from on to off
NG
Check the PPWR panel power relative circuit,
Q300, Q303 In normal operation, when LED =green,
R308 should =0 v,
If PPWR no-response when the power switch
Turn on and turn off, replace the U200-GMZan3
OK, FB401 have response
NG, no Voltage
Measured the Q300 pin 2= 3.3 V?
Check U202 pin 74,77,80=3.3V
OK
OK
Replace Q300 ( N-mos, AO3401)
Yes
Measured the inverter connector CN400
Pin1 on/off control=3.3V (on)
Pin2 PWM signal control dim 0V-5V when
adjust the brightness
NG
Check the Bklt-On relative circuit, R400,
In normal operation, when LED =green,
R400 Bklt-On should =3.3 v,
If Bklt-On no-response when the power switch turn on-off,
Replace U202 GmZAN3
NG, still no screen
Replace Inverter board to new-one,
and Check the screen is normal??
OK
NG
Check NO SCREEN APPEAR block
OK