As part of a joblot, and because I wanted to play Metroid: Return of Samus, I got hold of this 3DS with multiple faults.
Firstly, it wouldn't always power up (it would flick on power then go off), and when it did the bottom screen was severely corrupted.
The bottom screen required a new display, and the power not working is a common problem with the Nintendo DS range. Specifically if the top display isn't connected properly - or if the ribbon cable is pinched from the hinge (a common fault), then during boot up tests the device will power down.
Luckily for me, I was simply able to reseat the ribbon connector and then swap out the bottom display and it was right as rain in 30 minutes flat!