Gave it a shot and there doesn't seem to be any shorts or blobs. Only seems to happen when the joycon needs to be charged. The right joycon seems to be normal.
Sounds like some short on the voltage line of the joycon rails.
Give your switch a thorough cleaning with IPA first.
Maybe some solder blob is shorting something out something when the joycon is connected,
If that is not the case, with a...
I modded this switch about a month ago. Shortly after the battery died and would no longer allow me to turn on the switch. I replaced the battery and am now faced with another problem. When ever the left joycon is connected the screen starts...
I recently modded a friends v2 switch with a picofly. Everything was working great but left the switch sitting for about a week. Now, when I try to turn it on with no charger plugged it has no signs of life. When I plug in a charger it boots...