LCD TV: No power, no standby. (Bush LCD27TV)

[ulric]

Hello there,
I have a Bush (LCD27TV) LCD TV which worked perfectly until today.
However it won't turn on anymore: no picture, no sound, no standby, no front led...
On one of my first attempts to switch it on this morning, it very briefly turned on, displayed some snow, and switched off again after less than half a second. Since then, it has never turned on again.
At first, when power was on I could hear a very faint high pitched sound from the top of the monitor, but can't hear it anymore.
I checked the wall socket and it worked perfectly well.
I opened the back of the TV but fuses don't look obviously blown, and no components look blatantly burnt.
The sudden onset of the fault and the fact that there doesn't seem to be any power going through the TV at all makes me think that the power supply may be faulty, but I may be entierly wrong!
Have you ever come across this kind of issue?
Could I fix it myself or should I call a repair man?
And if so, how much might it cost?
Thank you very much!