Hey, when I saw this topic I immediately recognized myself!
In fact, a few months ago my little brother inserted a compact flash into an old Supercard CF, but in the wrong side, which broke a pin connector, then when you insert this broken Supercard into a DS it blow a fuse, you can look over the forums there are tons of post reporting this issue, especially on www.scdev.org .
As he didn't understand why the DS was not powering on anymore, he tried my DS, and then my cousin's one. Yes, he blown up 3 DS only for a compact flash in the wrong side...
I searched on the internet, I understood the problem and I tried to fix it myself on his DS Lite this weekend: I opened up the case with a triwing ordered on eBay too, etc. I have not been able to repair the fuse since my soldering iron was very big so I went to a local electronic supplier and he did it for 2€ (yes, far cheaper than the 90€ asked by Nintendo!).
What the fuck? I lost the R shoulder during the operation! I can't find it anymore, I lost the shoulder button, the metallic axis and the tiny spring...
I saw on the internet people that are changing there DS cases, and there is buttons with the cases, so I could maybe have a case including the R button for 30€ but it's quite expensive just for a single button and I don't even know if there is the spring and the axis included! I don't think so..., so I'm fucked up with a DS lite without the L button?
If anyone have an answer, you're welcome to help me, it not, I hope you just enjoyed reading my poor story (sorry for my english
)