There are some things you can fix, and some things that you can’t.
When the display backlight lamp failed in my old trusty Compaq Armada E500, I figured I would just ‘pop in a new one’.
I repair all sorts of stuff, from power supplies, to TVs to Nintendo DS units. I can do component-level repair on SMD-based devices with a pretty good success rate.
My attempt to change the backlight bulb took over an hour and the end result is that it did not work. (I’m pretty sure I damaged a ribbon cable that was adhered to the display panel with copper-foil tape).
There are repairs that are fun, fast, and easy. This is not one of those. I’ve changed head gaskets on car engines that were easier and took less time than this.
Everything inside this display was all glued and/or taped down with foil tape, the replacement lamp leads were a bit too long, and you even have to make sure no solder blobs are on the lamp contacts, or it won’t fit back in the device.
It was a miracle that I did not break the replacement lamp..imagine a fluorescent lamp tube that is about the diameter of a toothpick and 15″ long (a $20 part).
So the lesson of the day: there are ‘serviceable parts’ and there are ‘non- serviceable parts’.
A VERY talented and skilled tech might be able to swap a LCD backlight on a laptop display, but I would guess most normal humans could not.