I wanted to play on my original GBA (AGS-001), but without a backlit screen, it's really difficult to stay interested. SOoooo, I decided to look-up modding it for a backlight screen!
You can replace the original non-backlit GBA LCD with an SP's screen. A pretty simple mod, all you need is to hook it up via a ribbon adapter cable found online, and with a little case modding and a few solder points you have a perfectly comfortable playing experience on your trusty GBA!
I was able to find 2 non-working GBA SP's as donors, I do not condone ruining perfectly working units for this mod, or any type of mod that needs donor parts.
Whenever I mod anything, I try to keep as organized and clean as possible. I use painters tape to keep screws and parts separated and like to write labels on the paper to keep track of where things go (of course in this day in age, we have cell phone cameras to help as well!). Here's are the parts disassembled for 2 GBA's.
I decided to spend a bit more money on getting the ribbon cable that has the 5-brightness settings, via toggling Select+L. I didn't want to put any janky switches into the case, and I prefer having more dimming options than just the 2-settings that a majority of ribbon adapters out there have.
Ribbon adapters connected to the SP LCD's:
Here are the tools I used for the case modding:
Only 3 wires to solder onto the mainboard:
And voila! Jimmy is happy!