Can anyone advise on a new problem with this slightly older TV?

37XV503D Toshiba Regza television, until now it has happily been working with a Tivo box and Playstation 3 (PS3), input through the HDMI ports. All 3 ports were working. This week, I turned it on and neither Tivo nor PS3 inputs are coming through (not getting video or audio), just blue screen. Both PS3 and Tivo are displaying LEDs as normal when powered up, and the TV is otherwise functioning as expected (menus etc). Oddly, plugging a PC in through HDMI still works, it displays PC screen fine from all three HDMI ports. The other odd thing is that you can still put the TV to standby by pressing the off switch on Tivo, as before...even though no picture, there's clearly some communication going on between the two.

I have tried:
- Cycling through all HDMI sources/inputs and switching each device to different ports
- Swapping HDMI cables (all three work with the PC in all ports, none work with other devices from any port)
- Checking connections (all seem tight and fine)
- Powering down, unplugging everything and waiting, then rebooting everything.
- Holding PS3 power button down to second beep when switching on to recalibrate (online forum suggested, this did nothing)
- Turning 'lip sync' off on TV's AV options menu
- Manuals for TV and Tivo...nothing of use.
- I can't see anything else in TV controls or menu that might help.

It's possible that a recent storm may have power surged devices maybe, but apart from this failure to recognise HDMI input, everything seems normal (surely you'd expect fuses gone etc, there is no sign of anything untoward). I am going to take PS3 and Tivo to a neighbour to confirm they both work as normal by plugging into another TV, but it just seems unlikely both devices failed simultaneously and still display normal lights etc.

What is going on? Perhaps I've somehow changed a setting? I'm not a techie, and don't know anything about HDMI interfaces.

Can anyone help? Many thanks all.