YH-J70 connects by MTP only - how do you activate USB mode

[chipowski]

Hi.
I have the YH-J70 black 20g version and can only get it to connect to my computer using MTP mode. This is useless to me cause you cannot transfer video, photos, firmware upgrades etc... just music.
I have hooked it up to 4 different pc's all running XP with WM10 and all of them are using MTP. I've tried with the supplied software and without but it makes no difference.

How do you get the stupid player into USB mode?
There is no visible option to do so on the player. In the connection settings on it, the choices are MTP, Charge, MTP+charge.
I've been trying for days to get this sorted and have had no luck at all and have heard nothing back from Samsung support.