Hardware How to force Joy-Con controller update?

[uyjulian]

Is it possible to force the update of the firmware of the Joy-Con, even when it's the latest version?

I have used Joy-Cons from eBay and the buttons on the right Joy-Con were not working. However, the analog stick and the pressing of it worked.

However, when I updated the controllers, the buttons started working again, even when detached. After I pressed the little button on the right Joy-Con, only the analog stick and pressing of it works, and the other buttons don't work except holding the little button for a scrolling indicator light.

 

[uyjulian]

I have an idea about what's going on. If one of the buttons are held, the Joy-Con will not respond until all buttons are released. The check was probably bypassed when the Joy-Con firmware was updated. The ZR button appears to be stuck, so I'll fix that.

 

[uyjulian]

Update. I fixed the left Joy-Con by replacing ZL flex cable and cleaning off corrosion. For the right Joy-Con, I've narrowed down the problem to the mainboard (with rail connector, battery, and mainboard only connected). I probably need to replace the right Joy-Con mainboard. However, it works fine after an update but before resetting without the ZR button, so is there a way to force an update even on the latest version?

 

[uyjulian]

I fixed my issue by washing the Joy-Con board in water and blowing compressed air under the chip.

It would be nice to have a way to update Joy-Cons on the Nintendo Switch, or maybe a port of Joy-Con Toolkit for the Nintendo Switch.