New 3ds shuts down after pressing L

Hi!

A 3DS that turns off with a pop means that there is a bad connection either with the speakers or the top screen. And both ribbon cables for those two parts pass right below the L button, so if pressing the button makes the system turn off, then there's definitely a bad contact in that area.

Unfortunately, there is no way to know precisely which part is faulty without opening the console and inspecting the area closely, but from what you're telling us i can see three possible sources of the problem:

• Top screen ribbon is damaged
• Speaker ribbon is damaged
• One of the connectors for those parts on the motherboard is damaged

Let's hope it's not the latter, because while replacing the screen or the speakers is doable with patience, replacing a connector on the board is impossible without solid knowledge and experience in micro soldering.