A couple of times while fiddling about in the timers/recordings menus or going/back&forth or something, working out how things work, somehow the video decoder seems to crash - the on screen menus, info bars, channel changing etc all works, audio works, but no video, just black. Cycling to standby and back doesn't fix it.
The only way to fix it is to hold down the power button for a full power off and then power on.
Running the latest firmware.
Has anybody seen this before, is there some known way of triggering it I can warn gran against, and is there some easier way to resurrect it rather than physically going to the thing, holding down the power, waiting for it to shut down, then pressing power again.