The LCD power inverter increases the voltage to the backlight so it illuminates brightly. Inverters tend to fail more often than any other part of the LCD assembly. Luckily they are one of the cheapest and easiest parts of the LCD assembly to replace. Since it is the easiest we always recommend you start by testing/troubleshooting the inverter. This article will aim to help you identify if you have a bad inverter and hopefully correct problems that may arise after you have attempted to replace the inverter in your laptop.
“What should I look for?”
The inverter provides power to the backlight of the LCD and usually results in the dimming of images on the screen to the point that it will not appear to be on. You may notice that the laptop will boot as usual but the backlight may then quickly turn off. You can check to make sure only the backlight is off by shining a flashlight on the screen. If you see a faint image then your inverter is most likely bad. If you do not see an image at all you may have another issue such as a burned out backlight or a bad lid switch. You may also notice a buzzing sound coming from the bottom center where the inverter is located.
“My LCD screen still doesnt work! Now what?”
Most of the time when you replace your inverter successfully your backlight will come on immediately upon rebooting your computer. However, occasionally the dim backlight issue will persist and you may find yourself frustrated and confused. Before giving up there are a few things you can do to troubleshoot the issue:
- Cables are not plugged in properly: Double check both cable connections to the inverter. This can seem too easy to be true but often connections can work loose when putting the LCD assembly back together. I have personally experienced this problem several times.
- The inverter is not compatible- Choosing the right inverter can be a bit tricky. LCD inverters are manufactured by just a few companies like Foxconn and Hannstar and are used in all the major brands and laptops that use a CCFL(cold-cathode fluorescent lamp) backlight. The problems most people have arise from the fact that these companies often will use a half dozen or more part numbers on compatible inverters for different laptop models (Like this one which replaces over 50 part numbers!). It is not uncommon to find that the inverter in your computer is compatible with other brands and models (This Inverter is compatible with models from Acer, HP, Toshiba and Lenovo)(If you are having trouble identifying the right replacement you can use our site www.machinaelectronics.com which allows you to browse inverters by model and also lists alternate part numbers for those inverters.)
- A burned out LCD inverter – Even though Machina Electronics ships all static sensitive parts in anti static bags they can be susceptible to problems caused by static shock damage. If you have a voltmeter you can check to make sure the inverter is receiving power. If the inverter is not receiving power you will need to try a replacement.
If after checking all three troubleshooting methods your LCD is STILL not displaying picture properly you may have another issue or a combination of 2 problems like a failing backlight / LCD ribbon cable, an LCD lid switch issue or even a problem on the motherboard. I hope this has been helpful! Keep checking back for future articles!