How to fix a 73 in mitsubishi tv that was struck by lightning?

Your probably have power supply damage, but lightning strikes can do major damage in all circuits.

If the power light doesn't come on then first look for a fuse. It's very likely a fuse. If all fuses are good and power comes on you might have lost a circuit board. Check eBay for boards. Part numbers are printed on them. They just unscrew and unplug. However it could be either board.

tried to reset the tv first, if struck by lightning the tuner will be damaged or the main board but since the tv is still working so i think not the lightning was the main cause.

No,Ur power supply board have a big jolt massive power search.It dead,change the power supply board,will solved this problems.Tries Shopjimmy.com,Ebay.com to buy a refurbish power supply board for the replacement.

I would have thought it will become obvious from the burnt parts and broken parts inside the amp, if it was struck by lighting, when you take the top off. But clearly unless it has an aerial connection, it will have to be from the mains lead that lighting went in to the unit, so a good look around the power supply section, I think first.
To be honest depending on the damage if you fix this one they should give you top marks!
Many service people would say no-chance!

As u have just said that it was struck by lightning the only way to get the TV back working is to replace burnt items on the moterboard .becouse lightning must have demaged some components on the power supply, if possible i would preffer a new power supply board

replace the power pcb in the tv.

You wont be able to fix the TV your self as the power circuit board may have blown - consult a qualified repair man. Buying a surge protector for your expensive electronic goods is highly recommended.

WOW!
Warranty voider there.
Hate to see a $1,000 TV go down the toilet.
If your lucky, you can try checking the fuses inside the TV.
The lightning may have taking out only your power supply board, shopjimmy.com may have replacements for about $100. But, I can't tell you for sure that will fix the problem.
You may have to take to a repair shop to find out for sure.
Good Luck

Looks like the flyback (high voltage transformer and probably the majority of the power board is kaput. It would be cheaper and probably worth your while to invest in a new TV rather than try to fix this one..