No option to repair failed iPhone 11 Pro Max microphone?

Apple does not do piecemeal work on most iPhones models, including the iPhone 11. They provided you a service replacement and then all the parts on your iPhone are recycled, they reuse almost everything in it they do not throw it away.

It sounds like the connection on your microphone has come loose, most likely from a drop, which is why the forced restart brings it back to life.

If you go the 3rd party route make sure they are a competent shop with a good reputation as if they don't do the replacement properly they may cause other damage and the loss of the use of Face ID. If you go this route Apple may refuse to work on your iPhone again.

Hello,

Hmm, unfortunately I can't answer your repair questions. However, rather than replacing the phone, or paying for a risky third-party repair, consider other microphone options:

1) the wired headphones contain a microphone

2) wire-less AirPods contain a microphone

3) Other third-party microphones

Note: you can test the various microphone options using the Voice Memos app.

Good luck.

In that case I would go the service replacement unit for junior if they are not familiar with technology. I use Ultimate Ears IEMs on some calls, sometimes the speakerphone, and sometimes the earpiece. At their young age they should be able to learn this stuff.