Hi Pete3232,
Welcome to the forum.
The most common problem is loose connections. Have you checked that the f plugs are very tightly secured to the cables? They come loose very easy if not securely fitted to cable. I would first undo f plugs from PVR and make sure f plugs are not loose, and make sure you tightly twist cables into plugs and then reconnect. (Turn off pvr first or you might get a shock – can happen).
If this doesn’t work, then you will need to investigate further. Please let forum know how you get on, if you need more help. John L