Hi,
I bought a used Kettler Racer S a few days ago. When I turn it on, it is all ok for a few minutes and then the screen turns off. Sometimes it turns off completely and other times it has a solid red circle and sometimes it has the top half of the red circle, then the bottom half and it constantly does that.

When it happens, the only way to clear it is to remove the power and then plug it back in.

Please help - Have I bought something that cannot be used?