Dell 1909Wf, Service Manual

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Service Manual
15
and through C101 filtering, C102 and C105 is 3.3V which supplies toU102
、
U106
、
U103
、
U201
、
U105
、
U108output filtering.
- +1.8V is generated from Regulator U102 which is supplied byU101-3.3V
through C106 filtering.TheU102 output1.8V via FB105 send to U105.
3. FACTORY PRESET TIMING TABLE
Standard Resolution Horizontal
Frequency (KHz)
Vertical
Frequency (Hz)
VESA
640 x 480 31.469 59.940
640 x 480 37.500 75.000
800 x 600 37.879 60.317
800 x 600 46.875 75.000
1024 x 768 48.363 60.004
1024 x 768 60.023 75.029
1152x864 67.500 75.000
1280x1024 48.483 60.042
1280x1024 60.087 75.034
1440x900 55.935 59.887
IBM DOS 720 x 400 31.469 70.087
4. Power On/Off Sequency
Hardware power On/Off
When power cord plug into AC socket, Power provides DC_5V to interface board.
DC_5V is main voltage for panel and Regulator U101.
DC_3.3V is coming from Regulator U101, DC_3.3v is main voltage for U105.
When DC_3.3V input to U105 and U105 reset circuit active, U105 all registers
will be set to default, that means finish hardware power on.
When pull out power cord from AC socket,the system shut down instantly for no
supply
Software power On/Off
- When press power key, U105 #4 receives low pulse, then
U105(TSUM5PEHJ-LF) will be wake up and send control signals(at 109,73pin)
to on CCFL and switch 5.0v to panel module, at the same time,U105 make the
VGA/DVI cable input signal source display normal on panel if the VGA/DVI
cable input signal is active
- If power ON, U105 #123 (LED_blue) will send out low potential, and then LED
blue on.
- If power saveing, U105 #124 (LED_Amber) will send out low potential, and
then LED Amber on.
- If power ON or power saveing, when press power key, U105 #4 receives low
pulse, then U105 will be sleeping and turn off backlight, at the same time, the
panel will lose +5V.
The Panel_Vcc, Backlight_En, CLK/DATA output to panel will follow the following
sequency.