ViewSonic VA902B - 19" LCD Monitor, Руководство по обслуживанию

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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 Resolution
H-Freq.
(KHz)
V-Freq.
(Hz)
Dot Clock
(MHz)
1 640 x 350 31.5kHz 70Hz 25.2
2 640 x 400 31.5kHz 60Hz 25.2
3 640 x 400 31.5kHz 70Hz 25.2
4 24.7kHz 50Hz 19.8
5 31.5kHz 60Hz 25.2
6 35.0kHz 67Hz 30.2
7 37.9kHz 72Hz, 31.5
8 37.5kHz 75Hz, 31.5
9
640 x 480
43.27kHz 85Hz 36.0
10 720 x 400 31.5kHz 70Hz 28.3
11 35.1kHz 56Hz 36.0
12 37.9kHz 60Hz 40.0
13 48.1kHz 72Hz 50.0
14 46.9kHz 75Hz 49.5
15
800 x 600
53.7kHz 85Hz 56.3
16 832 x 624 49.7kHz 75Hz 57.3
17 48.4kHz 60Hz 65.0
18 56.5kHz 70Hz 75.0
19 58.1kHz 72Hz 78.5
20 60.0kHz 75Hz 78.8
21
1024 x 768
68.67kHz 85Hz 94.5
22 1152 x 870 68.6kHz 75Hz 100
23 63.4kHz 60Hz 108
24
1280 x 1024
79.97kHz 75Hz 135
25 1280 x 720 45kHz 60Hz 74.2
4. Power On/Off Sequence
4.1 Hardware Power ON
When power cord is plugged into AC socket, SMPS starts work and provides U105 and U106 with
VCC5V. When VCPU inputs to U105, U105 resets circuit active, sets U105 all registers to preset modes,
and then U105 #43 sends out a HWRESET signal voltage to reset U104, 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, U105 #24 recieves low pulse, and sends out “Power on/off” order back to U104,
and then U104 will do the power on/off.
-
If Power ON, U105 #6 (LED_Green) will send out High potential, and then LED green on.
- If Power OFF, U105 #7 (LED_Orange) will send out High potential, and then LED Orange on.
The Panel_Vcc, Backlight_En, CLK/DATA output to panel will follow the following sequency.
7
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