Service manual

17
ViewSonic Corporation Confidential - Do Not Copy VA503b-2_VA503m-2
3. FACTORY PRESET TIMING TABLE
TIMING
F
H
(KHz)
F
V
(Hz)
Sync
Polarity
Total
(Dot/Line)
Active
(Dot/Line)
Sync Width
(Dot/Line)
Back Porch
(Dot/Line)
Pixel
Freq.(MHz)
31.469 + 800 640 96 48
640x350@70Hz
70.086 − 449 350 2 60
25.175
31.469 − 800 640 96 48 IBM
640x400@70Hz
70.086 − 449 400 2 35
25.175
31.469 − 900 720 108 54 IBM
720x400@70Hz
70.087 + 449 400 2 35
28.322
24.700 − 800 640 96 48
640x480@50Hz
50.000 − 494 480 2 8
19.760
31.469 − 800 640 96 40 VESA
640x480@60Hz
59.940 − 525 480 2 25
25.175
35.000 ( 864 640 64 96
640x480@67Hz
66.667 ( 525 480 3 39
30.240
37.861 ( 832 640 40 120 VESA
640x480@72Hz
72.809 ( 520 480 3 20
31.500
37.500 ( 840 640 64 120 VESA
640x480@75Hz
75.000 ( 500 480 3 16
31.500
43.269 ( 832
640 56 80
VESA
640*480@85Hz
85.008
−
509 480 3 25
36.000
35.156 + 1024 800 72 128 VESA
800x600@56Hz
56.250 + 625 600 2 22
36.000
37.879 + 1056 800 128 88 VESA
800x600@60Hz
60.317 + 628 600 4 23
40.000
48.077 + 1040 800 120 64 VESA
800x600@72Hz
72.188 + 666 600 6 23
50.000
46.875 + 1056 800 80 160 VESA
800x600@75Hz
75.000 + 625 600 3 21
49.500
53.674 + 1048 800 64 152
VESA
800*600@85Hz
85.061 + 631 600 3 27
56.250
49.726 − 1152 832 64 224 MAC
832x624@75Hz
74.550 − 667 632 3 39
57.283
48.363 − 1344 1024 136 160 VESA
1024x768@60Hz
60.004 − 806 768 6 29
65.000
56.476 − 1328 1024 136 144 VESA
1024*768@70Hz
70.069 − 806 768 6 29
75.000
60.023 + 1312 1024 96 176 VESA
1024*768@75Hz
75.029 + 800 768 3 28
78.750
57.700 − 1360 1024 136 144
1024*768@72Hz
72.125 − 800 768 6 26
78.472
4. Power On/Off Sequence
4.1 Hardware Power ON
When power cord is plugged into AC socket, SMPS starts work and provides U103 with VCC3.3V. When VCC3.3V
inputs, U103 resets circuit active, sets U103 all registers to preset modes, and then monitor goes into stand-by
mode. That means hardware power on has been completed.
4.2 Software Power ON/OFF
When press power key, U103 # 90 recieves low pulse,and then U103 will do the power on/off.
- If Power ON, U105 # 91(LED_Green) will send out Low potential, and then LED green on.
- If Power OFF, U105 # 91(LED_Green) will send out High potential, and then LED Off.
The Panel_Vcc, Backlight_En, CLK/DATA output to panel will follow the following sequency.