On my Samsung TV there is a 'No signal power off' which I think defaults to 30 minutes.
Msy be worth changing that time to see if it makes any difference.
Apologies for the late reply, SHMBO has got me decorating and the box problem is on the backburner
I can't find any mention of a loss of signal setting but all the "eco" settings are off.
I have managed to do a "fix" for the time being at least. I have connected the YVB to my blue ray player, instead of directly into the TV and the system has now been running OK now for almost 24 hours with no shut down.
At least I am not getting any earache when the TV turns itself off on a regular basis.
Many thanks for all your help with this problem,
The "temporary" fix has stopped working, it has even started shutting down whilst watching recorded programs.
The TV turns itself off (no setting for loss of signal) shortly followed by the youview box restarting.
I can uderstand a poor aerial signal causing problems but why does it appear to lose signal whilst viewing a recorded program?