Started off with update from windows 8 to 10 ,ran OK for 3 to 4 weeks,then started getting unmountable boot coming up at start up,would clear itself then run as normal.when I now try to boot I've a blank screen and no cursor,plug it in to Tv to check if there was a problem with the screen it's black on there too.tried F keys to let me in to safe mode etc noothing there.when I tried to connect to another laptop it does show as connected device.could it be the motherboard or graphics