The control stick module itself is responsible for the sound. This noise is meant to happen when the clicker switch on the flexible PCB is pressed down. If your L3 input still works and the Joy-Con is not exhibiting unusual behavior or resistance when moving the stick, I wouldn't worry about this. If functional issues come about as a result of this matter, the most convenient method of resolution is changing your control stick module. For the left Joy-Con, you can do this by following this guide, which is also available below for your reference. In the future, be wary of using excessive force when pressing the L3 and R3 buttons, which is a potential cause of failure. I hope your problem is resolved without too much trouble.

There are a few avenues you can take for a problem like this. Check another set of Joy-Con or combination of them to isolate the problem to the controller(s) or the Console as a preliminary step if possible. Regardless, consider the following options: (1) After unpairing all previous controllers/wiping the Switch's pair history, try to sync your Joy-Con wirelessly and not directly. (2) Update your Switch if it isn't on the latest firmware and restart it- something you may have already done. (3) Go to the Controllers and Sensors menu and select Update Controllers. Reset your Joy-Con and see if they work right. (4) Put your Switch in Airplane Mode and change the settings to allow controllers to connect. Connect your Joy-Con in this state. Maybe one of these methods will do the job.

It's good that you've managed to isolate the problem to the Joy-Con specifically. The damage you've found on the ribbon cable (from my understanding) is also a valuable clue that helps validate the likely need for a replacement of the Joy-Con rail, which that same cable is a part of. The first step I'd take is cleaning the connector of the rail with contact cleaner like IPA and a swab or similar. Do this while the Joy-Con is off and see if the problem persists. This helps ensure that your problem is not caused by debris, which would necessitate the replacement of any components. Confirm that the ribbon cable is properly seated to rule out that being a potential cause as well. The next step I'd take -if possible- would be to get a Joy-Con of the same side and swap the rails to determine whether or not that is the true source of the malfunction. If the Joy-Con works correctly with the alternate rail, then you can be fairly certain that's the part you'll need to replace. If it does not work correctly even...

It sounds likely that the cooling fan is no longer functional. If that's the case, consider this guide (also available below) as reference for the installation of a replacement. There's the possibility of another component causing the loss of the fan's functionality, but that would require more thorough evaluation.

Out of curiosity, is the issue intermittent? Have you considered checking the connector for the lower ribbon-cable on the Joy-Con's motherboard to see if a trace, pin, or other element is damaged? There may be merit in that avenue of investigation.

If the analog sticks are not responding correctly, Hori recommends the following solution in the manual for the Split Pad Pro Attachment Set: "Disconnect and connect the controller from the Nintendo Switch or Nintendo Switch Dock and turn ON the Nintendo Switch. Once Nintendo Switch is ON, rotate the analog stick 2~3 times. The process above will only work when this product is attached to the Nintendo Switch™ console and the power supply is on." The Split Pad Pro Attachment Set is not compatible with the Nintendo Switch calibration menu. In the case that the accessory's dedicated recalibration option does not work, it's possible that you have control stick drift. The solution in that case is the cleaning of the potentiometers or a replacement of the control stick module. A reference for disassembly is provided here. I hope that your problem is solved in a quick and simple manner.

While an iFixit contributor has made a guide here, there's generally no a need to disassemble a 3DS game cartridge for cleaning. If the problem is cleanliness, it's the externally visible contacts that are typically the culprit. Saturating a cotton swab with high-concentration isopropyl alcohol or electrical contact cleaner and going over the contacts of the cartridge can be a sufficient solution to a lack of function on that front. If you haven't done so, give that a try before pursuing more intrusive measures. Give the cartridge a few minutes to dry completely and try it again. If you have to get into the cartridge, it may very well be some other kind of problem that you're dealing with.

If no left Joy-Con controllers will charge, then it seems likely that your issue is with the connector of the left rail on the Switch tablet itself. Disassembly and cleaning of the contacts with high-concentration isopropyl alcohol or electrical contact cleaner may restore function if there's no damage. Alternatively, a replacement of the associated ribbon cable or the entire rail are options you may consider. I've attached an iFixit guide here that goes over replacing the entire assembly for reference. I hope you manage to diagnose and resolve the issue without difficulty. EDIT: Here's a link to another answer I've given that's relevant to my advice in the comment section. For cleaning (as well as investigation of damage for one end of the cable) this should be helpful, as it includes visual reference. The solution presented there was for intermittent function in handheld mode, but that's a symptom of the same problem area. In your case, function without charging implies the charging line/trace in...

Your description indicates that the console is fine, but that this particular game is what has a problem. Consider cleaning the contacts with a cotton swab saturated in high-concentration isopropyl alcohol or another electrical contact cleaner. Read issues can be caused by dirty contacts, and a proper cleaning is one of the simplest potential solutions. Give it a try and give the contacts a few minutes to dry completely before trying the cartridge. I hope that it'll do the job and that nothing more intrusive will be necessary.

There is no plain 2DS XL. For the 2DS line, there's the Nintendo 2DS, and the New Nintendo 2DS XL. The categories of Nintendo hardware on iFixit include the same console twice under two names, so that may contribute to unnecessary confusion. These are not actually two separate consoles, and I agree that combining them together may be sensible if the teardown in the Nintendo 2D XL category provides value that can bolster the versatility of the resources in the New Nintendo 2DS XL category. Nintendo's naming conventions were a tad odd at the time. I can only say that the power difference between the standard and 'New' series governed likely governed the hardware under each classification despite the confusion some may find through it. The original 2DS has the same power as the original 3DS line. The New Nintendo 2DS XL has power that's in line with the 'New' series 3DS hardware. I hope this helps clear up any misunderstanding.