I have been having problems with our Humax YouView+ box for several months now. It'll be working just fine then the screen will go blank, no picture or sound. If you change the channel or press the menu buttons, the graphics still show i.e. "003 ITV" but still no picture or sound. The only channels which work are the internet channels like BT Sport. I have to switch the box off at the back and turn back on to get the picture back. It can then work for hours or days until the problem re-occurs. I have by-passed the YouView box and plugged the aeriel directly to my TV, which works fine so I know it isn't an aeriel problem. I have tried different hdmi cables, which hasn't made a difference. I have tried several maintenance options which work for a few days but then I'm back to square one. I've noticed that the box does get very warm sometimes even though it is well ventilated, and that the fan isn't spinning.
Any advice welcome as it's driving my partner & kids up the wall!!