How to Test LCD Inverter Boards

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Learn to test your LCD screen's inverter board.

Your LCD screen's inverter board is one of the most important components of your LCD screen assembly. The inverter board is a small circuit board inside your LCD screen that supplies power to your LCD's backlight device, which lights up your LCD screen and allows you to view images, graphics and videos on your screen. If it goes bad, your LCD screen may start to go dim or go completely black. One easy and important way to troubleshoot your LCD screen's inverter is by testing it to see if it is sending and receiving power.


Step 1

Turn off your LCD screen and disconnect your LCD's power cable from the nearest electrical outlet. If your LCD screen is part of a laptop, shut down your computer and then disconnect the power cable and all peripheral devices from the computer. Allow 10 to 20 minutes for the LCD screen to cool down before disassembling your LCD screen.


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Step 2

Remove the front panel of your LCD screen. Do this by locating and removing the Phillips-head screws that are securing the front panel of your LCD screen. You may also have to use a small, flat-head screwdriver to pry off the front panel after the screws have been removed. Be careful not to damage the LCD screen while doing this.


Step 3

Locate the inverter board inside the bottom edge of the LCD panel just below the LCD screen. Turn on your Multimeter device and enable "DC Mode" on the Multimeter. Attach the positive (red) probe to Pin 1 on the inverter board. There are two power cables connected to each end of the inverter board. Pin 1 is a small piece of metal protruding from the upper right-hand corner of the inverter board. Touch the negative (black) probe to any bare screw on the LCD screen.


Step 4

Turn on the LCD screen and wait for the Multimeter to take a reading. If there is absolutely no activity on your multimeter, that means your inverter board is bad. Turn off your multimeter and put it away after you have finished testing the inverter and then power off your LCD screen.

Step 5

Replace the front panel of the LCD screen and its retaining screws.

Things You'll Need

  • Phillips-head screwdriver

  • Flat-head screwdriver

  • Digital Multimeter


Use an electrostatic wrist wrap to prevent Electrostatic discharge (ESD) from damaging your LCD screen while testing the inverter board.