Factory Preset Timing Table; Power On/Off Sequency - Dell E190Sf Service Manual

- +5V is from switching mode power supply for panel and Regulater U601
- +3.3V generates from Regulater U601 supply for U401, U301, U402 used.
- +1.8V generates from Regulater U602 through C603, C604 filtering which is output +1.8V for U401
used.
3.

FACTORY PRESET TIMING TABLE

Standard
VESA
IBM DOS
4.

Power On/Off Sequency

Hardware Power ON
When power cord plug into AC socket, Power provides 12V,&DC_5V from through U850, DC_3.3V be
generated from DC_3.3V Regulater U601.DC_5V is voltage for panel, DC_3.3v is main voltage for
U401. When DC_3.3V input to U401, U401 reset circuit active, set U401 all registers to default,. That
means finish hardware power on.
Software Power ON/OFF
When press power key, U401 #125 recieves low pulse, and then (gm2621-LF) U401 will be wake up and
send high plus(at 127,49pin) to on CCFL and switch 5.0v to panel module. And make the VGA cable input
signal source display normal on panel.
- If Power ON, U402 #57 (LED_Green) will send out High potential, and then LED green on.
- If Power OFF, U402 #56 (LED_Amber) will send out High potential, and then LED Amber on.
The Panel_Vcc, Backlight_En, CLK/DATA output to panel will follow the following sequency.
Resolution
640 x 480
640 x 480
800 x 600
800 x 600
1024 x 768
1024 x 768
1152x864
1280x1024
1280x1024
720 x 400
Horizontal Frequency
(KHz)
31.469
37.500
37.879
46.875
48.363
60.023
67.500
48.483
60.087
31.469
11
Service Manual
Vertical Frequency
(Hz)
59.940
75.000
60.317
75.000
60.004
75.029
75.000
60.042
75.034
70.087