Wednesday, January 20, 2016

ViewSonic VX2235 LCD monitor Troubleshooting - Mstar ISP Toll - Power supply circuit - STR-W6200 - Back light Inverters circuit - LCD Monitor repair and service - Manual Service

Category: LCD monitor Repair and Service 

Contents of this article 

  • Troubleshooting
  • Power supply circuit 
  • Back light inverter Circuit 

ViewSonic VX2235 

Mstar ISP Tool
Setp1: Take the cable of Print Port to connect Print Port of PC and Print Port of fixture(and EDID burn in the same fixture) to connect VGA Cable between D-sub of fixture and D-sub of AD Board of monitor,the monitor must be turned on the power.
Step 2 : Open ISP Tool V4.3.4
Step 3 : Press ”connect” into ISP mode,display the model of Flash,The dialog of figure is displayed “Device Type is Pm25LV512” then press ”Confirm”.
Step 4: Press ”Read” then enter,then press READ to down load the program of BIOS (*.bin).
If down load BIOS that is successful then press ”Confirm”.
Step 5 : Press ”Auto” into below figure that display the value of BIOS Checksum below figure is displayed “0x1626” then press ”Run” to execute the BIOS procedure.
The BIOS procedure is displayed the message ”Verify OK” that the BIOS procedure is successful
Step 6 : Press ”Dis Con” then leave the mode of ISP
Step 7 When select ”ReConnect” and press “Run” then repeat to connect the mode of ISP into next the action of BIOS procedure
Troubleshooting Flow Chart
No power
# Make sure power button (or switch) is ON.
# Make sure A/C power cord is securely connected to the LCD display.
# Plug another electrical device (like a radio) into the power outlet to verify that the outlet is supplying proper voltage.
Power is ON but no screen image
# Make sure the video cable supplied with the LCD display is tightly secured to the video output port on the back of the computer. If the other end of the video cable is not attached permanently to the LCD display, tightly secure it to the LCD display.
# Adjust brightness and contrast.
# If you are using an Macintosh older than G3, you need a Macintosh adapter.
Wrong or abnormal colors
# If any colors (red, green, or blue) are missing, check the video cable to make sure it is securely connected. Loose or broken pins in the cable connector could cause an improper connection.
# Connect the LCD display to another computer.
# If you have an older graphics card, contact ViewSonic® for a non-DDC adapter.
Control buttons do not work
# Press only one button at a time.
STR-W6200D PWM Off-Line Switching Regulator
The STR-W6200D series are power ICs for switching power supplies, incorporating a power MOSFET and a current mode PWM controller IC in one package. Including a startup circuit and a standby function in the controller, the product achieves low power consumption, low standby power, and high cost-effectiveness in power supply systems, while reducing external components.
Switching power supplies for electronic devices such as:
# White goods
# Consumer electronics
# Office automation
# Industrial equipment
# Communications equipment
1 D/ST - MOSFET drain and input of the startup current
2 – (Pin removed)
3 S/OCP - MOSFET source and input of Overcurrent Protection (OCP) signal
4 VCC - Power supply voltage input for Control Part and input of Overvoltage Protection (OVP) signal
5 GND - Ground
6 FB - Input for constant voltage control signal
7 FM/ELP - Capacitor connection pin for frequency modulation and input of External Latch Protection