- Android Phone: Settings/About Phone. Tap [Build Number] 7 times. After the first few taps it confirms you are on the right track
- Android Phone: Under Settings, search for [Developer options], and turn on [USB debugging]
- Android Phone: Still under [Developer options], tap [Select USB configuration], and select [MTP (Media Transfer Protocol)].
- PC / Android Phone: connect a USB cable between the two. Yes, sometimes a cable will allow charging, but fail silently when you are trying to connect. However, I find that is pretty rare. As you connect, assuming Audio is on, you should hear a confirming sound from the PC, at least. If things have gone REALLY well, you will see something like this in Windows Explorer:
Although I often forget the steps (hence this blog, at last), if I get to this point, then the subsequent file transfer from PC to Phone or tablet always succeeds, at least in my experience.
At the end of the file transfer session, probably good practice to turn off USB debugging.