Have you tried rebooting it?
Today, I was being a dumb consumer, trying to get my TV working. How hard can it be?
The TV was silent with a blue screen, not good. The sky box was being unresponsive. Hmm.
Power cycled the sky box, which is usually all you need. Still blue screen. At one point I got some sound and a blue screen.
OK, give in, turn off the whole lot for 30 seconds... Power on. The sky box is feeding an image over HDMI on the boot up "Sky+HD, please wait". So that works...
Yay, after much waiting (why do things take any time to boot?) we get an image. The sky demo channel, but not sound. Try another channel, no joy.
The Bose sound system is off. OK, well, I did power cycle everything. But I can't turn it on (power button or remote). Check leads, plugs, etc. No joy, WTF?
OK, so I switch to TV speakers - still no sound. WTF?
OK, so, lets try one thing at a time. Tell TV to go on to iPlayer. Arrg! Loud... Turn down TV speakers, still loud. Hang on? The Bose is on, and working and on high volume. Turn that down, switch TV speakers off.
Back to sky and still no sound. Arrrg.
OK, change channel on Sky and magically we get sound.
All is working again.
But WTF! Why is this not easy? Why does it not just work FFS...
I diagnose equipment and networks and hardware and software as my day job. But I have no idea from this which of three boxes was ill, or why, or what it was actually doing. What hope do ordinary consumers have in the face of this?