We finally have an answer as to what has caused the desynchronization issues for the left Joy-Con for the Nintendo Switch: it was a configuration mishap at one of the manufacturing plants.
According to Gamespot, a Nintendo rep revealed to them that they identified the problem and have resolved it at the source, saying that a manufacturing variance affected some of the left Joy-Cons that were being produced for the Nintendo Switch…
“There is no design issue with the Joy-Con controllers, and no widespread proactive repair or replacement effort is underway,”
“A manufacturing variation has resulted in wireless interference with a small number of the left Joy-Con. Moving forward this will not be an issue, as the manufacturing variation has been addressed and corrected at the factory level.”
It was determined by GameXplain in a troubleshooting video that there was some kind of interference issue with the Joy-Cons, but only surmised that it may have been due to blockage of the signals. Others claimed that the issue was persistent even when nothing was blocking the wireless connection of the Joy-Cons.
Nintendo saying that the issue is resolved means that the next batch of Nintendo Switch units shouldn’t have any desynchronization issues.
For those still having problems, however, you can either troubleshoot the problems yourself or send the units back to Nintendo for repair, they further mentioned in the statement to Gamespot…
“We have determined a simple fix can be made to any affected Joy-Con to improve connectivity.”
“There are other reasons consumers may be experiencing wireless interference. We are asking consumers to contact our customer support team so we can help them determine if a repair is necessary. If it is, consumers can send their controller directly to Nintendo for the adjustment, free of charge, with an anticipated quick return of less than a week. Repair timing may vary by region.”
There’s also a variety of YouTube videos online that explain how to troubleshoot the problem if you don’t want to send the unit in for repair to Nintendo.
YouTuber The Gadget God has a simple three minute video to help guide gamers through fixing the issue for those who suffer through the problem.
Unfortunately, Nintendo did not say what the failure rate was for the Joy-Con desync. All we know is that a small number of units were affected during a manufacturing batch. Sony suffered a similar problem with a slightly bent HDMI port on the PS4 during launch, and it was due to some issues that were occurring at a Foxconn plant, where high-school students were brought in to help work the assembly line but were allegedly being mistreated, including two students who had reportedly been raped.