When your display turns pink, cuts out after a few seconds, or doesn’t show any picture, your backlights are out. This common problem can be repaired at a relatively small cost when compared to that of buying a new panel or terminal.
Troubleshooting a backlight problem is relatively straightforward, however changing the backlights on a panel is a tedious process that requires a very steady hand. This article will highlight some key points to replacing the backlights on your display; however let the professionals at Gremark Technologies Inc. complete the LCD repair.
After diagnosing that it is a backlight issue, and not a board or other component repair, open the unit. Opening the unit consists of removing the stand, separating the plastics, and removing the housing screws along the chassis.
Please note that before removing the housing screws near the chassis, gently unlink all cable connections from any components that are impeding the removal of the frame. If the terminal is a touchscreen, there will be a connecting ribbon, be very sensitive when disconnecting this ribbon.
Once the unit is open, remove the LCD panel. The LCD panel is connected to the chassis with several screws along its edge or frame, remove all the screws and remove the panel from the chassis. The LCD panel will have a driver board on the back, remove it. The driver board controls the signals displayed on the screen, be careful not to bend the pins or damage this component.
After removing the driver board, there will be several layers of reflective coating used for luminance that need to be peeled. Behind the reflective surface there are wires from the inverter to the Cold-Cathode Fluorescent Tubes (CCFT’s), these tubes contain the backlights for replacement. Disconnect the tubes and replace the lights, the backlight tubes carry a current, conduct all repairs on a grounded surface.
Note that the display will only appear properly if all the screws and connectors are re-assembled correctly. Without tightening the screws and refitting all the aluminum foils/metal layers properly, there will be interferences on your screen. Also, any dust particle or contaminate will be present on your screen at startup, clean the screen thoroughly.
Upgrading the panel from LCD to LED displays is a popular option with newer technology. With an LED upgrade, the tube CCFT’s are replaced with LED light strips. The LED light strips have a longer shelf life and pull less current from the power source. Gremark Technologies Inc. can upgrade a variety LCD panel to LED technology. For more information on backlight repairs, leave a comment or contact us.
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