How to test whether inverter board or laptop lcd backlight is bad.
A lot of people always mistake everytime the screen of their laptop goes dark, and that they always blame the inverter board. So they buy inverter boards and only to find later that it did not fix the issue… But not often the culprit is the inverter board. The following simple test will tell whether the inverter or light bulb or commonly called backlight is defective.
1. remove the pink and white (high-voltage) connector from the inverter board. At this point we assume that proper handling of LCD is observed. That means, power from AC adapter or battery is removed, otherwise electric hazard is eminent.
2. Get another LCD screen, whether a used one, as a testing-LCD with a known bulb to be working properly, and connect the pink and white (others use blue/white and other colors) connector to the inverter. At this point, we don’t need to connect the data/video cable from the systemboard to the back of the testing-LCD.
3. Replace AC power adapter or battery so that we can power up the machine to test whether the bulb is going to be lighted. Make sure that you do this at a short period of time, like 5 secs, or just until the bulb is lighted. If there is no light at all, then we conclude that the inverter is bad. If the bulb of the testing-LCD is lighted then we conclude that we have to replace the backlight of our original screen.
Here’s the video tutorial on how to test whether the inverter board or lcd backlight / bulb is defective.