Why shouldn't it be worth fixing? It's only 4 years old, my own TV is 15yo, I fixed it twice but it's still kick'n! You have a problem in the power supply, do you have electronic's know how? And test equipment? Soldering equipment? If so we could walk you through it, If not A repair man should only cost 80 to 100 to fix it.
TV was working fine this morning, then all of a sudden it switched itself to standby and will not switch on with the remote and if i switch is off at the button and then back on again, the red standby light comes on but it wont "fire up" inside the set - Is it worth repairing as its about 4 years old