Hmm. Firstly Tills are you sure that the machine wasn't updating and had not completed? Can you access settings by pressing the windows key or right clicking the windows icon bottom left if it is there? If so go into settings (cog wheel) and look in update and security. In there look if there are outstanding updates . If not look for the recovery option. This could get a bit techie thereafter Tills.
Sounds to me Tills that a Windows update installation isn't completed yet, or it is not completed successfully. Have you tried switching it off and waiting a while then booting up again?
I switched my Windows laptop on yesterday and it had updates. It is annoying when the screen is black as you are not sure what is happening if anything. It took a while so it may help to wait and see. If egg timer is flickering on and off then it is more likely it is updating.
Daft thing is when you are online and using the devices you can set and upgrade loading and still use the machine, but if an upgrade launches whilst you are not online you cannot open it up.
If you have time to wait for an answer .. Google 'windows 10 updates causing problems'
Microsoft are constantly issuing updates that once installed may cause you issues. MS themselves are actively advising Win 10 users to delete certain recent updates.