Teletext is not working. If I switch off the power completely and put it back on, it comes on, and has worked like that for a while. Now however it only comes on for a short while, and then I am unable to use it without again switching off the power and putting it back on again.
An easier and less stressful way of doing a soft reset than using the power switch is to touch and hold and the front panel standby button for eight seconds or so.