Hardware Nintendo switch left joycon draining battery when idle

[jetuaime81]

I have a perfectly working left joycon of a v2 switch (hac-001(-001)). The joycon works when plugged in or wirelessly and charges properly. However when off, the battery drains to 0V over time and i tried swapping battery but it's still the same. I measured and checked the a good joycon jumps upto 20mA draw when voltage is applied and idles at 0.5 to 0.8mA

But this left joycon has an idle draw around 8mA which is why it is draining the battery Anyone encounter this issue or any suggestions?

Post automatically merged: May 4, 2025

Update: i reflowed (heat and nudge) the main BGA chip. Everything works and idle draw has come down to 4mA.

Reballing is possible but the board is weird in the sense besides the bga pads, there are many vias' that are exposed (which I am seeing for the first time, usually they are concealed).

 

[jetuaime81]

Update 2: took off the IC reballed and checked still the same. Battery draining due to idle 4mA current draw.

 

[thesjaakspoiler]

Have you tried updating the firmware of the controller?
(Settings -> Controllers -> Update controllers)
Nintendo did update the firmware for the joy cons 1 or 2 times so maybe that will fix this problem.

You can check the current firmware version with the Joycon toolkit :
https://gbatemp.net/threads/tool-joy-con-toolkit.478560/

 

[jetuaime81]

Have you tried updating the firmware of the controller?
(Settings -> Controllers -> Update controllers)
Nintendo did update the firmware for the joy cons 1 or 2 times so maybe that will fix this problem.

You can check the current firmware version with the Joycon toolkit :
https://gbatemp.net/threads/tool-joy-con-toolkit.478560/

Yes I did try the update firmware it said already updated. Is there a way I can force the update again?

But that was before 20.0 released. I haven't updated the switch because I read a lot problems people facing after 20.0.0 and 20.0.1 updates thought il wait a few days.

 

[jetuaime81]

Have you tried updating the firmware of the controller?
(Settings -> Controllers -> Update controllers)
Nintendo did update the firmware for the joy cons 1 or 2 times so maybe that will fix this problem.

You can check the current firmware version with the Joycon toolkit :
https://gbatemp.net/threads/tool-joy-con-toolkit.478560/

Joycon firmware version is on 4.19. i wanted to ask you, if I backup the spi of this board and restore to another working board, will the serial number and Mac address also transferred?

I saw AliExpress sells board alone for like 8usd so. I just want it be authentic to be sure I don't get banned. I read many posts that I won't be banned but this is a still a big question for me.