Tv video module problem

[beema_geeza]

Hello just done tv retrofit on 2014 F06 Gran Coupe with NBT.
I've done quite a few of these without any problem until now.
After selecting tv, I get picture but no sound and it switches back to radio or whatever I was listening to before (with sound working)
It seems a comms problem on the fibres.

Dis says to replace tuner that works fine in my F30. My tuner does the same in the F06. Tried another NBT in the F06 just incase software issues but it's the same.

I'm wondering what item on the most would affect or conflict with the video module.

Thanks

1CA,1CB,1CC,1CD,223,230,2NM,2PA,2VB,302,323,337,3A G,423,428,430,441,481,494,4KS,4MR,4ND,4NE,4U2,4UR, 508,552,5A1,5AC,5DL,5DP,601,609,610,654,688,698,6A C,6AE,6AK,6AM,6AN,6AP,6NS,6WB,710,715,760,775,7S9, 812,850,853,877,880,8KA,8S2,8S3,8SM,8TF,8TG,9AA