Hardware New 3DS XL L & R buttons stuck

[Scarfhero]

Today I went to play my 3DS to find that the L button was stuck in a pressed input. The triggers didn't appear to be stuck. I cleaned just hours before and tried to make the L button unstuck but the R button became stuck too in the process. If this seems confusing to you I can further elaborate

 

[TurdPooCharger]

Whatever cleaner you used must have gunked up the the shoulder buttons mechanism.

You can try reviving them with this risky procedure if your n3DSXL is not disassembled. Otherwise, it's better to re-clean them with the shoulder buttons taken off.

The currently partially NOT-tested-in-real-life, improper method of ...
How to (attempt) fixing/cleaning the R-shoulder button without (full) disassembly
... because you have katsavidiphobia [aka, "the fear of screwdrivers"].​

Other than that, you might need to outright replace them:

• [iFixit] Nintendo 3DS XL 2015
  
• [eBay] For Nintendo New 3DS New 3DS XL/LL Console L R ZR ZL Button Ribbon Flex Cable