I'm sort of surprised by this, but that GBA SP I picked up with the non-working backlight is not fixable. I say this is surprising because Nintendo products are built like tanks. There was a news story a few years ago about how a guy's house got flooded and all of his Nintendo consoles (caked in dirt) still functioned perfectly. Do that to an Xbox or a PlayStation and it's done for.
I went out and tracked down a multimeter today, hoping that the problem with this SP was similar to the one that the Russian guy in the video demonstrated. Not so. Also, if you get a cheap multimeter, don't trust the packaging. The package said it tested continuity. It didn't, because it was just a generic backing that this company used for all of the different multimeters they sell. The only way to see the features the one that you actually bought has is to open the blister pack and read the instructions. It wasn't a huge problem, though. I just used it to measure if there was a current actually getting through the ribbon cable to the screen, and there was.
So, that was out. Next I checked the fuses, and they were all fine. So, I decided to just go ahead and bypass the ribbon cable anyways and solder wires between the points where power for the backlight gets to the screen. I already knew there was a current getting to the screen, but I figured I ripped it apart already and it's just two wires. No dice.
We have a genuinely burned out backlight on our hands. It may not necessarily be burned out, but something is going on in the screen that I can't fix. I'm not too heartbroken about it; I don't particularly like the feel of the SP. I'm not too sure what I'll actually do with it, though. There's a couple of options here...
1. Just keep it for spare parts. Maybe I'll come across a screwed up working one some day.
2. Get a replacement screen from a Chinese seller.
I'm sort of entertaining option two. Why a Chinese seller? You can get OEM screens from Taobao for about $20 US. If you buy them from an American seller, it'll be at least $60 and those guys are just getting them from Taobao and adding a premium onto it.
Option two brings up another issue, though. There is a seller on Taobao who makes an adapter so that you can use a GBA SP screen in an original GBA. I prefer the feel of the original GBA way more than the SP. If I'll already be ordering through Taobao, then what's the harm in just picking up one of those adapters?
Then the next step in my thought process is to just buy two replacement SP screens, get the adapter for the fat GBA and then sell the white one on eBay since they're pretty valuable.
Either way, the SP is on the back burner for now.