Hardware Encountered strange bug tonight

[TheCyberQuake]

I'm going to start out by saying this is the one time this bug actually happened, so I don't have proof and it's definitely not some major problem with the Switch.
Anyway, tonight I went to play my switch in tabletop mode to resume a mk8d. Upon waking it up, my right joycon connected just fine, but the left one wouldn't even turn on. I just thought it was dead, so I went to slide it into the switch to charge. But then nothing. No switch snapTM, absolutely no signs of life from the left joycon. That's when I started to worry.
So naturally I start troubleshooting. disconnecting and reconnecting the joycon to no avail. So I dug up my gray joycon and tested those. Right joycon connected, but again the left joycon didn't even want to turn on or connect to the system. That's when I started to get really confused and panic. The problem even persisted after rebooting the switch.
Luckily, after mashing buttons and frantically detaching and reattaching the left joycon, I started to get signs of life again as if nothing had ever been wrong.

I honestly can't comprehend how that even happened.
Firstly, both left joycon (with near-full charges) showed no signs of life, not even the normal led syncing indicator when you push a button. I can maybe understand a brief connection issue, but not one that somehow forces any left joycon to not even turn on.
Secondly, both of those joycon also failed to work with a direct connection.

I honestly can't come to any logical conclusion of what kind of hardware bug or failure would cause that, and I major in IT. I'd be interested to hear what others think the cause was or if they have had any strange single-time bugs like this.

 

[Kikirini]

I've actually had this exact same issue. Multiple times. Dunno what causes it.

 

[Akshuls]

This happened to me on the very first day of booting it up.

 

[Selver]

... Upon waking it up, my right joycon connected just fine, but the left one wouldn't even turn on. ... No switch snapTM, absolutely no signs of life from the left joycon. ... [a different] left joycon didn't even want to turn on or connect to the system ... both of those joycon also failed to work with a direct connection.

I recommend sending them in for repair under warranty. I have experienced this on various joycons, always the left ones.

 

[Meteor7]

This happened to me twice, but pressing the pair button on the edge of the joycon fixed it immediately both times.

 

[Tumoche]

i had the same problem or a similar, my joycon would not connect to my switch attached, it would connect by bluetooth for some reason
I solved it by pressing the pair button on my joycon (its also a power button)

 

[Slattz]

This has also happened me, pressing the pair button on the joycons fixed it.

 

[TheCyberQuake]

I recommend sending them in for repair under warranty. I have experienced this on various joycons, always the left ones.

It's only ever happened that one time, and I have never had any other issues. I'm not going to send it to them for what appears to be more a software bug than anything can really be repaired, especially since it's only ever happened once in the 5 months I've owned it.

 

[Rodrigo Mafra]

This happened to me once, with the left one too!!! So, after hours detaching and reattaching the left joycon, it come back to life.

 

[DarkFlare69]

It happened to me a day or two after getting the Switch and hasn't happened since then

 

[CTCaer]

Happened to me also, before months. I could replicate it around 6 out of 10 times. It's a bug on Joy-Con firmware.
When it turns off, it hangs. But I can't remember how to replicate it again though..

The sync button is a kill switch. It actually completely turns off the device.
That's why it works after that. It does a cold boot.