Tv gets red light on, then blue light shines, fades out and turns off, unable to power up the TV. I've tried unplugging, pressing power button on TV etc, nothing works.

I should say my TV is 42" Hitachi 1080hd :)

Most failures I see on Flat screens is the Capacitors on the Power Board, where the cord plug into.
Many can be seen bulging and not test equipment is necessary to further test.
If confident you can dissemble and reassemble. Can't hurt to look.

Many Thanks, we're not very good with electrical things, is this something that a repair guy could fix?

They would have to be able to dissemble and reassemble, and to desolder and resolder Capacitors.
Many videos on YouTube.
Try "Cap replacemnt on flat screen".
I don't know if I seen one using what I think works well, is a Desoldering Iron from Radio Shack.

Free 40" Samsung Flat Screen - TV FIX - YouTube (http://www.youtube.com/watch?v=OS_p-1ihl0U)
I tried the search and that is what I came up with.
Will see if I can find the desoldering iron. Back in a minute.

Here is a video of the desoldering iron in action.
Take note the rotating of the lead while heating up and removing, helps to get solder from all around the lead.
TV Repair Desoldering made EZ - YouTube (http://www.youtube.com/watch?v=wBngvmpNe5A)

What's the model number of the Hitachi? I haven't seen any Hitachi sets with bad caps on the power supply. Although that doesn't necessarily mean that this is not the cause of the problem (just means I haven't seen it).

I figured for someone with limited knowledge may be able to SEE a bulging cap, and they don't have to pay someone.
If not a fuse or cap, they will need a Manual, or Pay someone.

I figured for someone with limited knowlege may be able to SEE a bulging cap, and they don't have to pay someone.
If not a fuse or cap, they will need a Manual, or Pay someone.

True. I was curious of the model since I know some of the Hitachi sets have problems with the power supplies (but if I recall correctly it required the whole board to be replaced as there was a new version). I could be remembering incorrectly though.