Nintendo DS Lite
Shoulder button repair

April 6, 2022

Previously I had worked on a Nintendo DS Lite which had been picked up for parts.  I had cleaned up the cartridge slot to get it working, but after a button test I determined that one of the shoulder buttons needed some attention.  Well, the replacement shoulder buttons for the Nintendo DS came in, so it was back to the bench.  I suspect that these little suckers will be difficult to solder as the contacts are under the component.  I don't have access to an oven for reflow, so I would need to use a hot air station and try not to melt anything on the switch.

A strip of ten Nintendo DS Lite should button tactile switch replacements.

New shoulder switches. So tiny.... 

Putting a little thought into it, I suspect that the dome spring contact having lost it's 'springy' nature from previously cleaning the oxidation off. While I tried to reform the spring I think it was just too beat up. But, with the new switches I have an opportunity to steal a new dome spring without needing to desolder the old switch.

A new Nintendo DS Lite shoulder button tactile switch which has been separated into parts.

New shoulder switch, disassembled for harvesting 

I carefully took apart one of the new switches, and I noticed that they are slightly different. The push button is a larger diameter. Luckily the dome spring seemed to fit OK into the old switch housing. I carefully closed up the switch after replacing the dome and gave it a little test. It still didn't feel right, I wasn't able to get a good 'snap' from the switch. The front plate on the switch housing which had been peeled open a number of times was worse for wear, and I wondered if maybe it was interfering with the actuator. Although the new switches have a slightly different front plate, it looked similar enough that I thought it was worth a try to swap it in. Because the diameter for the push button is larger I also swapped in the new button. Carefully closing everything back up, and it seemed like I was getting a much better snap. The switch felt much better.

New shoulder button switch soldered to a Nintendo DS Lite main board.

The replacement dome, plunger and front plate in place.  The soldering looks a little thick on the front, this will be cleaned up later.

I reassembled the DS and then ran Diagnose to test the buttons.  Good click, things felt great but.... the button still wasn't registering well.  I'm guessing that under the dome switch there is still internal oxidation which is preventing a good connection.  I had received a new shell for the unit so I will need to tear it all apart again anyway, but I was really hoping that this was going to be the end of the shoulder switch saga but it wasn't to be.