ViewSonic Vx2255wmb-2 Service Manual

Control Explanation
Resolution Notice allows the user to enable or disable this notice.
If you enable the Resolution Notice show n above and your computer is set at a 
resolution other than 1680 x 1050,  the following screen appears.
OSD Position  allows the user to move the OSD menus and control screens.
OSD Timeout  sets the length of time the OSD  screen is displayed. For example, 
with a “30 second” setting,  if a control is not pushed within 30 seconds, the 
display screen disappears.
OSD...

4. Circuit Description 
4.1 Switching Mode Power Supply 
4.1.1 AC Current Input Circuit
 
P801 is a connector for connecting AC Power. F801 is a fuse to protect 
all the circuit. AC input voltage is  from 90v to 264V. R801 and R802 joined 
between two inputting main circuit to prevent man from shock. L801 is used 
to clear up low frequency wave. C801  and C802 are used to discharge the 
waves that L801 produced. High frequency waves are damped by C801 and 
C802. D801 is a rectifier which composed  of 4...

 
4.1.4 Feedback and OVP Protect Circuit 
Pin R of IC803 is supplied 2.5-v stab le voltage. It connects to 5V and 
14V output through R822, R823 and R824. R822, R823 and R824 are output 
sampling resistor. When the sampling voltage more than 2.5V or less than 
2.5V, current of FB IC802 will change, this can change the voltage from 
T801.   OVP Protect Circuit: When output is  overvoltage, the auxiliary winding 
voltage will be increased, when it reache s about 14V. Q803 is triggered . It 
makes the...

4.3    I/F Board Circuit  
4.2.1 Power  Input
 
- +5V is converted to 3V3(U101) and 1V8(U102) for U104. 
- +5V is fed to LVDS panel via Q101. 4.2.2  Scalar & MCU
 
- U104 (TSUM58WHJ) is a scalar IC with MCU. 
- U104 #77~#100 output 8 bit LVDS digital data to panel control circuit through 
CN104.  - U105 is a flash memory IC for program. 
- U107 and U202 is a EEPROM IC. 
4.2.2 VGA  Input
 
- The Red,Green,Blue input signals  come from CN103 #1,#2,#3 into TSUM58WHJ 
analog input terminals #28,#25,#23 via...

protector to prevent U104 from ESD. 
 
- Digital clock DCLK+,DC LK- from CN201 #23,#24 pass es through D208,D209( for 
over voltage protection),R216,R217  and then goes into U104 #5,#6. 
 
 
 
4.2.4Button Control
 
Button “Key-Power” is defined as power on/of f, which is connected to U105 # 90 through 
CN105 # 6.  Button “Key-2” is defined as two functions  of selecting and adjustment, which is connected 
to U105 #94 through CN105 # 5.  Button “Key-Up” is defined as plus, which is connected to U105 # 95...

 66.667 −  525 480  3  39   
37.861 
−  832 640  40  120 VESA 
640*480@72Hz 
72.809 −  520 480  3  20  31.500 
37.500 
−  840 640  64  120 VESA 
640*480@75Hz 
75.000 −  500 480  3  16  31.500 
35.156 + 
1024 800  72  128 VESA 
800*600@56Hz 
56.250 +  625 600  2  22  36.000 
37.879 + 
1056 800  128  88 VESA 
800*600@60Hz 
60.317 +  628 600  4  23  40.000 
48.077 + 
1040 800  120  64 VESA 
800*600@72Hz 
72.188 +  666 600  6  23  50.000 
46.875 + 
1056 800  80  160 VESA 
800*600@75Hz 
75.000 +  625 600  3...

75.231  − 1,728 1,280 136  224 1280*960@75Hz 
74.857 +  1,005 960  4  38  130.000 
49.405  
−  1,680   1,280   128   200  1280*1024@50Hz
49.853  +  1,057   1024  7   23   88.500  
63.981 +  1688 1280 112  248 VESA 
1280*1024@60Hz
60.020 +  1066 1024 3  38  108.000 
79.976 
+ 
1688 1280 144  248 VESA 
1280*1024@75Hz
75.025 + 
1066 1024 3  38  135.000 
47.712  
+ 
1,792   1,360   112  256  1360*768@60Hz 
60.015 + 
795   768  6   18   85.500 
54.113  
−
 
1,848   1,400   144   224  1400*1050@50Hz
49.965 +...

 
  T1 (ms)  T2 (ms)  T3 (ms)  T4 (ms) T5 (ms) T6 (ms)  T7 (ms) 
0.1~10 0~50  >200  >100  0~50  >0.1  >1000 
 
4.6 AC Outlet Pin Assignment 
                                  
Pin Symbol Description 
1 L  Live 
2 N  Neutral 
3 E  GND 
 
 
4.7  Inner Connector Pin Assignment 
4.7.1 CN501, CN502, CN503, CN504 (
Connect to Panel Backlight, 
SM02B-BHSS-1-TB or equivalent
) 
Pin Symbol Description 
1  H.V.  High voltage for lamp 
2  L.V.  Low voltage for lamp 
   
 
 
 
 
 
 
P801
12
3
 25 
ViewSonic...

4.7.2CN101 (Power BD to Interface BD) 
Pin No. Symbol Description 
1 VCC5V +5.1V INPUT 
2 VCC5V +5.1V INPUT 
3 GND GND 
4  ON/OFF  CCFL on/off control 
5  BRIGHTNESS  Panel luminance control (CCFL brightness) 
6 GND Ground 
7  VOL  Volume control input   
8  MUTE  Mute control input   
 
 
 
4.7.3CN105 (Interface BD to Keypad) 
Pin 
No. Symbol Description 
1  LED_ GREEN    Orange LED lighting control 
2  LED_ ORANGE  Green LED lighting control 
3 GND  Ground 
4  KEY_POWER    DC power on/off control, 
5...

 
4.7.4CN104 (Connect I/F BD to panel, FI-X30S-H or Equivalent) 
Pin No. Symbol Function 
1  RXO0-  minus signal of odd channel 0(LVDS) 
2  RXO0+  plus signal of odd channel 0(LVDS) 
3  RXO1-  minus signal of odd channel 1(LVDS) 
4  RXO1+  plus signal of odd channel 1(LVDS) 
5  RXO2-  minus signal of odd channel 2(LVDS) 
6  RXO2+  plus signal of odd channel 2(LVDS) 
7 GND  Ground 
8  RXOC-  minus signal of odd clock channel (LVDS) 
9  RXOC+  plus signal of odd clock channel (LVDS) 
10  RXO3-  minus...