Please try to boot into Android recovery menu and perform reboot or even factory reset from there.
1. Turn off player.
2. Hold down volume wheel and top left button at the same time, hold until Shanling logo appears. If performed successfully, image of green robot and “No command” text will appear.
3. Hold down volume wheel and while holding it down, turn it one step clockwise.
4. Now you entered Android Recovery menu. Use volume wheel up/down to go through menu and press volume wheel to confirm. Wipe data/Factory reset option can be found in the middle.