flat plastic (an old credit card will do)
Old-style GBASP (the one without the brightness options)
Original GameBoy Advance
20-60ohm Resistor (I just stole a 200k one from a joystick and it worked fine, so this is a very loose requirement)
Ok, here we go.
Obtaining your light
The first step has no pictures; sorry.
1. Take your GBA SP, and open it. There are five rubber covers on the top portion covering up triwing screws; take off the "rubbers" (oh, so funny) and remove the screws.
2. Using your old credit card plastic thing, seperate the GBA SP faceplate with the logo text on it from the LCD assembly.
3. Seperate the LCD from the light assembly (the thing closest to you)
4. Desolder (or just rip off) the two-wire cable connecting the LED to the back of the LCD.
5. Now that you have two portions (The bare LCD, and the black frame holding the light), take the rubber border off of the black light frame. You should see a polycarbonate slab, as well as a metal strip. CAREFULLY remove these, trying not to seperate the three components (small LED, light bar, and slab) If you do, it's okay, but you'll have to tape them together later.
6. Reassemble the GBASP if you wish to; it'll still work, just no light.
Inserting the Panel
7. Remove the six triwing screws on the Original GameBoy Advance, and the one phillips in the battery compartament.
8. Remove the three motherboard screws with the phillips screwdriver.
9. Disconnect the LCD cable on the top by pushing the two tabs on the sides of the ribbon holder away from you.
10. Remove the motherboard.
11. Take out the buttons, side trim, and shoulder buttons. Do not forget the power switch!
12. Pry up the LCD using your scrap plastic card thingy of doom.
13. Place your GBASP-obtained light panel assembly where the screen was. Make sure the gritty side is facing out the screen, and the leads are going out the bottom!
14. Replace the screen. It's okay that it does not stick in place; just use some tape to keep it there. Once the unit is assembled it will not matter.
15. Solder wires to both leads of the panel, about 2 inches long each.
16. Using a 3 volt source, test which lead should go to the ground, and mark it so as to not mix it up later.
17. Now we are brought to a choice of where to obtain voltage.
: Use the pins on the cartridge slot.
Now, when the GBA is playing GB/C games, it gives the cartridges 5V instead of the normal 3V. Thus, one can not use the cartridge power directly, as switching to GBC mode will fry the backlight.
OR WILL IT?
Many report that this voltage switch does occur, but using my GBA and my multimeter I verified that my cartridge connector outputs a constant 5V no matter what is in the slot. Maybe there exist multiple revisions of the GBA that change this.
Anyway, you'll need that resistor, or else your panel will look very bright, then quickly fade and never come back
Make some 1.5-inch wires of IDE-cable thickness or less to those points.
: Take the voltage from VCC
This method has an advantage in that 1) it requires no resistor as VCC is 3V and 2) the soldering is done on the back of the motherboard, meaning you can do this all without propping your GBA motherboard up at 45 degrees. The trouble is that you must slice your select buttons to make room for the wires, and might ruin them.
This is in the lower-right corner of the GBA on the back.
Now that you've got little leads going everywhere, it's time for the next step.
Fitting it all together
18. With the LCD panel in place on the top half, put all the buttons and such back in.
19. Reconnect the LCD to the motherboard.
20. Don't put the motherboard down yet! If you took option 1, take the leads you made (to GND and S2 on the cartridge) and make sure they are occupying that little empty region below the cartridge slot. Now
put the motherboard down, so the leads are still visible.
21. Solder the lead going from GND onto the motherboard to the proper lead coming from the LCD, and the others respectively. Do not forget the resistor somewhere in this!
If you took option 1, skip to step 23.
22. Since you took option 2, take one of the leads for the panel you made earlier and solder it to the [-] terminal on the GBA. Solder the other wire to VCC. IF you mixed them up and it does not work, just switch them.
23. Pack the cables into that empty area below the screen. Keep the wires away from the screw hole in the centre! Make sure you insulate them too. If the wires are on the foamy area, this is okay. Just make sure they do not overlap on the foam area, as this puts pressure on the LCD.
24. Reassembly your GBA and enjoy!
Get smart and install some Antireflective Film onto the GBA LCD for a better image. I stole the AR film from the SP, and it looks so much better than in that picture (which is still good!)