Right Joycon not working when docked, but my Switch still detects it and does the animation

Hi guys.

My wife dropped the Switch by a little bit while playing in handheld mode. When we picked it back up, the right joycon wasn’t detected. We tried redocking it to little avail. However, whenever we did redock it, it did the snap sound and the little animation on the right.

The joycon works fine while wireless. When we try to dock it while connected wirelessly, it disconnects. As a note, when we look at the controllers settings on the Switch while attaching the joycon, it briefly says it is charging and then the wireless turns off on the joycon and it is no longer showing.

We know it is not the switch as we were able to attach other joycons on the right and they all work fine, which narrowed my search to the joycon in question. I opened it, and I thought I noticed that the ribbon cable connecting the rail to the battery was slipping out. I disconnected the battery and while I was doing that, the entire rail ribbon came out of the joycon. I placed it back in, but I damaged the black receiver thing for the cable. Nonetheless, I got it in, but still got the same results as previous… the joycon works fine, shows that’s it charging briefly when I connect it to the console, and then the wireless cuts out and the switch no longer detects it.

A bit at my wit’s end trying to figure this out. Also tried all manner of updating controllers, disconnecting and reconnecting them, factory resetting them and what not. No matter what, it plays the animation and the sound, but won’t activate handheld mode. Should I keep my focus on the ribbon cable and try to fix it? I thought maybe the damage I did to the receiver would render it unusable, but I get the same symptoms before and after.

I have some experience with fixing JoyCons (repaired about 12 or so thus far) so hopefully I can help. The first place I would start is by double checking the pins on the rail aren’t bent or damage from the fall. You can also do a continuity test on the pins of the rail to the pads on the ribbon to make sure none of the joins broke during the falls. I don’t have a pin out handy for that but you shouldn’t need one for this.

As for the connector for the rail, is the plastic latch broken on it? The connector itself is replaceable with a little flux and the right amount of hot air though it can be a little tricky to get the right amount to not melt it. I ordered a dozen or so of the rail and SR/SL ribbon connectors from Aliexpress but I have seen them on eBay as well.