I have just signed up for a new contract with BT. I installed the box, which seemed to work at first. Today, it was randomly crashing and now won't turn on at all, there are no lights showing. I'd rather not reset it or I will lose my recordings which I haven't yet watched.
It is possible to do a factory reset and start again without losing recordings in Maintenance Mode. I am not suggesting that you should do this or that it will solve your problem, but if you do want to try it:
https://support.youview.com/youview-box/box-and-remote/using-maintenance-mode/