The Nintendo DS is a portable video game machine with two LCD screens, one of them a resistive touch-screen. The processor is an ARM chip.
The DS failed to switch on and failed to respond when connected to a charger. At first, I suspected the lithium-ion battery, but that appeared to be OK when tested. With a bit of searching, I found that a common failure mode is the on-board fuse(s). These fuses are surface-mount parts, soldered to the main PCB in the machine.
Referring to a web-page that describes the fault, I tested the fuses. Sure enough, one of them had failed.
The unit can be opened up by unscrewing several tiny screws from the case. Most of these screws are so-called "tri-wing" screws, intended to thwart the repairer. I had recently acquired a tri-wing screwdriver from Deal Extreme, SKU 19861. It fitted the screw heads very well. Note that two of the screws are hidden under the rubber feet of the machine, on the same edge as the screen hinge.
There are two fuses in the DS, but in my case only F2 had blown, a 750mA 0603 size fuse.
I obtained a replacement fuse from Farnell. It's a tiny part, but solderable with a very fine tip, good lighting and a stereo microscope.
Reassembly is the reverse of disassembly.