3dscapture.com

Interesting. Looks like the N3DS board will need an update, it doesn't like the modified timing. https://3dscapture.com/tmp/3ds_capture_20240508.zip Let me know if there's any other weirdness with this version. There's a lot of other changes under the hood, including an audio rewrite from over here.

It sounds like maybe the configuration got lost? Same thing that happened here. I'm not sure how, that's not supposed to happen accidentally like that. https://3dscapture.com/tmp/3ds_capture_20240508.zip Run this. Hold Shift when you plug the 3DS in. It should detect an unconfigured device and repro...

Shouldn't be a problem.
Here's what it looks like inside: https://3dscapture.com/install_old/15.jpg

Also test different USB ports on your computer.

It is probably the soldering.
Did you install it yourself?

No, that's not a problem.

You can use any shipping service.

Either address will work.
You don't need to put the phone number on the package. It's provided because sometimes shippers will ask for a phone number.

Do you have any particularly bad examples? If you haven't already, you should change your 3DS sound from surround to stereo. Audio is passed up to Windows to do the resampling, it isn't done by the capture software. I tried using WASAPI instead, you can give it a try. I'd be surprised if there's any...

Hmm. Sounds like you've done all the troubleshooting steps I would have recommended. You could try connecting it to a different computer and see what happens.
I'll take a look at it if you want to send it in.