It is too hard.
I bought a ND2300 OTG from others. The version shows as Nexto-CF v1.032.
I pressed down reset and then copy. When never how long and combination I did pressing, the otg always went into PC mode or x-copy mode, depends if the USB cable connected.
Tried tens of times, still can not go into upgrade mode.
Any trip to go to upgrade mode? or my otg is not upgradable?
Problem found. The reset button died. I opened the box, jumped the two pins of the reset button with a piece of wire to replace the pressing of button. It worked!
The reset button is least pressed button, but it died. I really hope other components are not so weak like that junky button.