MP4 Onda VX757 on the functions of the problem, your thoughts

I lock the key is set to open, listening to music or the radio when the plane would return home, but after a period of time, how are inextricably locked and no longer by the MODE button useless, can only be shut down.
but if this feature does not return home and has a long face can be solved by the MODE is.
how this is going on in the end, this machine is not the problem?