Dell E2009W Service Manual page 32

Service Manual
Power(include IF +5Vand +3.3V) supply normal but LED off and no
display
Is the key function OK?
Is the low active reset signal at #108 of
IF Board U105 normal?
Is the PWM signal at #125 of IF Board
U105 normal when power AC on?
Upgrade Firmware to Serial Flash U108
by VGA port with ISP_ Tool V4.100.exe
Power(include IF +5Vand +3.3V) supply and display normal only LED off
Is the keypad cable connective OK
Is LED at keypad work OK
Is theLED control signal at 123# of U105
high-low convertible when DC on/off
NO
Is the frequency 14.318MHz at
#127,#128 of IF Board U105?
Yes
Yes
Yes
END
Yes
Yes
Is R165 open?
NO
Is Q107 work normal?
Yes
END
31
Yes
Press power key to DC on the monitor,
if display ok the process is end, if no
display see the no backlight process
NO
NO
Yes
NO
NO
Reassembly or changing
NO
Change LED
yes
Change R165
NO
Change Q107
NO
Change U105
Change crystal X101
Change C164
NO
Change U105
Change U105