Factory Preset Timing Table - ViewSonic VA702-1 Service Manual

3.4 VGA Input
Signal R, G, B, SOG input through CN102 #1, #2, #3, and C115, C116, C117 and C118 filtering the
high frequency noise. Signal HSYNC and VSYNC input through CN102 #13 and #14, and C119, R119,
C120, R120 filtering. Then the analog signal enters U104, and then U104 deals with it internally. In
addition, TVS101, TVS102, TVS103 (the three are BAV99), TVS104, TVS105, TVS106, TVS107 (they
are constant voltage diode of 5V6) are ESD protector. Signal DDC-SCL inputs via CN102 #15, and then
passes through TVS107 for ESD protection, goes into EDID EEPROM IC U103. Signal DDC-SDA
inputs via CN102 #12, and then passes through TVS106 for ESD protection, goes into EDID EEPROM
IC U103. CN102 #5 is defined as cable detect pin, this detector realizes via R107 and U105 #4. The
PC-5V of U103 is supplied by PC via CN103 #9 with D103 for ESD protection, or supplied by Monitor
self via D104.U103 is an EEPROM IC, which is a kind of memory and used for saving EDID data.
3.5 Button Control
Button "Key-Power" is defined as power on/off, which is connected to U105 #24 through CN106 #4.
Button "Key-2" is defined as two functions of selecting and adjustment, which is connected to U105
#25 through CN106 #1.
Button "Key-Up" is defined as plus, which is connected to U105 #26 through CN106 #3.
Button "Key-Down" is defined as minus, which is connected to U105 #27 through CN106 #5.
Button "Key-1" is defined as two functions of menu and exit, which is connected to U105 #28 through
CN106 #2.
LED indicator on the front bezel is defined as follows:
a. When press button "Key-Power", U105 #6 is pulled down and U105 #7 is pulled high, so Q104 is
conducted and the LED indicator is green.
b. When in power-saving mode, U105 #6 is pulled high and U105 #7 is pulled down, so Q105 is
conducted and the LED indicator is orange.

3. FACTORY PRESET TIMING TABLE

Item
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
ViewSonic Corporation
H-Freq.
Resolution
640 x 350 31.5kHz
640 x 400 31.5kHz
640 x 400 31.5kHz
24.7kHz
31.5kHz
35.0kHz
640 x 480
37.9kHz
37.5kHz
43.27kHz
720 x 400 31.5kHz
35.1kHz
37.9kHz
800 x 600
48.1kHz
46.9kHz
53.7kHz
832 x 624 49.7kHz
48.4kHz
56.5kHz
58.1kHz
1024 x 768
60.0kHz
68.67kHz
1152 x 870 68.6kHz
63.4kHz
1280 x 1024
79.97kHz
1280 x 720
V-Freq.
(KHz) (Hz)
70Hz
60Hz
70Hz
50Hz
60Hz
67Hz
72Hz,
75Hz,
85Hz
70Hz
56Hz
60Hz
72Hz
75Hz
85Hz
75Hz
60Hz
70Hz
72Hz
75Hz
85Hz
75Hz
60Hz
75Hz
45kHz 60Hz
Confidential - Do Not Copy
20
Dot Clock
(MHz)
25.2
25.2
25.2
19.8
25.2
30.2
31.5
31.5
36.0
28.3
36.0
40.0
50.0
49.5
56.3
57.3
65.0
75.0
78.5
78.8
94.5
100
108
135
74.2
VA702-1_VA702b-1