c110 scanner not working

For some unknown reason my C110 OB2 scanner has ceased working . I own a 318i e46 m43 1998 model. I have been using it and has worked fine up to now . Normal procedure , plug in scanner and it powers on ,then turn on key to first or second position and start diagnosis. Now I plug it in and it powers up but when I turn key on I cannot get any response from scanner, it stays on initial power on page , none of the buttons do anything, no menus no nothing. Can anyone suggest what the problem may be? A fuse or relay maybe? If so which one . . I am waiting on new fuel pump and filter so car is not running at moment ,but this has never affected scanner operations before.Battery still holding about 12.3 volts. Any ideas would be greatly appreciated

Cheers Buckannear