A dim laptop screen doesn’t mean the screen is bad. If your laptop is suddenly too dark to read, but you can still see the image on the screen, it’s quite possible your inverter board is going bad. The inverter is a small board at the base of the monitor that converts the DC current coming from the motherboard into AC current the screen requires. If the inverter fails, your screen can go dim or completely black.
If the screen is completely black and you can successfully connect an external monitor, then you could have a problem with the inverter or the backlight bulb. Unfortunately, there is a trial and error process involved in determining if the problem is with the inverter or the bulb. You should also take the first obvious step of making sure the brightness is turned up on your laptop. There is usually a function key at the top that allows you to quickly adjust the brightness of the monitor.
Dim Laptop Screen – Replace Inverter
If you have a dim laptop screen , you should replace the inverter. It can usually be accessed simply by removing the front bezel of the screen. Most laptops will have hidden screws or tabs, so be sure to consult your service manual before attempting to pry the bezel off. As with any laptop repair, the laptop should be off, unplugged and the battery should be taken out. The laptop inverter will plug into either side with a ribbon cable and screw into the display to hold it in place.
Note: If you’re unsure which inverter to install, remove the defective part and look for the number on the back.
Dim Laptop Screen Complications
Laptop repair, unlike normal PC repair, is usually best performed by a professional who has the proper diagnostics and knowledge of specific laptop models. In the end, a laptop DIY repair can cost more than taking it into the shop. With that said, there are a lot of serviceable parts on a laptop and the inverter is one of them. Replacing it should fix the dim laptop screen.