My Dell latitude D620 laptop is working fine but my screen is very dim, I can still make out what it says on the screen but it’s pretty difficult. When I turn the system on it has never flashed at full brightness, it just remains dim. I called Dell tech support and they said I need to replace the entire LCD screen, which I hope isn’t the case. I thought it would be the inverter or the backlight but they said the backlight and LCD aren’t separate entities, but that the LCD screen would have to be replaced to solve the problem. I’ve tried reconnecting a few different things under my keyboard to no avail. please help!
Most likely this problem is related to the inverter board witch you can replace without replacing the entire display assembly. Yes, on Dell laptops the inverter board is a part of the LCD screen, but you still can remove and replace the inverter board without replacing the LCD screen. Check out these instructions for taking apart the display assembly on a Dell Latitude D610 laptop. Take a look at the first six images. You can find a new LCD inverter for your Dell Latitude D620 here, it’s not expensive.
Also, this problem could be related to the backlight lamp (CCFL bulb) witch is located INSIDE the LCD screen. If that’s the case you’ll have to replace the whole screen. Alternatively, you can disassemble the LCD screen and replace just the backlight lamp but it’s not easy. You can easily damage the screen while replacing the backlight lamp. Anyways, here I posted instructions for replacing the backlight lamp.
Finally, this problem could be related to the motherboard or the video cable, but it’s not common.