Thought I had it working but now I get the following behavior:
Connect 5v from a transformer to C41 and Lynx 2 powers on nicely.
ONN Battery is charged but if I hook up the type A usb +/- pins to C41 right after pressing ONN button, the LEDs on ONN immediately turn off and the lynx screen does not power on.
But if I disconnect ONN type A USB wires from Lynx C41 and press ONN button (ONN LEDs turn on) and test tyoe A USB +/- with multimeter, I do get 5v.
Seems like whenever the Lynx2 draws current from ONN, the ONN shuts down.
Still tinkering ...