Dell UltraSharp 2208WFP, Service Manual

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Service Manual
36
Power(include IF +5Vand +3.3V) supply normal but LED off and
no display
Power(include IF +5Vand +3.3V) supply and display normal only
LED off
Is the frequency 14.318MHz at #15,#16
of IF Board U108?
Change crystal X101
NO
Yes
Is the low active reset signal at #4 of IF
Board U108 normal?
NO
Change U108
Yes
Is the serial clock and date signal at #33,
#35 of IF Board U108 normal when
power AC on?
Change U108
NO
Is the keypad cable connective OK
Reassembly or changing
Yes
Is theLED control signal at 1# of U108
high-low convertible when DC on/off
NO
NO
Change Q107
Is the key function OK?
NO
Press power key to DC on the monitor,
if display ok the process is end, if no
display see the no backlight process
Yes
Upgrade Firmware to MCU U108 by
VGA port with ISP_ Tool V4.100.exe
Yes
Is R165 open?
yes
Change R165
Is Q107 work normal?
NO
Yes
Upgrade Firmware to MCU U108
NO
Is LED at keypad work OK Change LED
NO
Yes
END
END