Sound but no pic (get menus fine)

[adm]

This is weird.

Was going to attach a pic of what it's set at (have also tried all combinations of downmix etc for all options)

The downmix etc. is only for audio that you indicate there is no problem.

Have you tried decreasing the video rate to 1080i or even 720i?
HD UK TV is 1080i and NOT 1080p.
For 1080p you may need a better HDMI cable (not necessarily a more expensive one)
Over the years as the resolution and bit rates have increased the HDMI specification has added different "versions" of cable to support these faster bit rates

https://en.wikipedia.org/wiki/HDMI#Versions

If you are using a lesser cable (one of the earlier versions) then it may not support the bit rates that you are attempting to push out from the box. It may just be intermittant at high bit rates..
The latest spec of cable shouldn't cost any more than a fiver.


Try also having the TV switched on before switching on your box.