Make the USB Connection on Your Android Phone Default to File Transfer Mode « Android :: Gadget Hacks
Android USB Connections Explained: MTP, PTP, and USB Mass Storage
Can't Find PTP/MTP Mode, How to Fix
Connecting in MTP mode
No USB MTP/PTP menu? Just dial *#0808# to enable USB Storage Connection Mass Storage Mode — Android 4.4.4 (Samsung Tmobile Galaxy Note 4), Ubuntu 14.04, Windows 8 | orange narwhals
Activate MTP ( Media Transfer Protocol ) on Android 7.x.x - YouTube