Hitachi projection TV Model 43F300 has no picture or sound?

one of your color tube has gone out on you.

it sounds as though you need to have the tv converged

BAD STKs YOU have 2 of them replace them both 392-110s up grade 180s.

Convergence kit # X480306 for your Model #.....
Replace parts & activate auto-focus......T.

you possibly have a deflection or convergence fault.

units in shut down to protect further damage,poss. power supply or deflection fault

Depends on how old it is and what the model number is. Do you think all TV's are the same man? No they are not.

power supply is bad

is the light blinking?

Sounds like it is going into shutdown mode. When the TV power supply and system control sense an overload the system control turns the TV off to prevent further damage from happening. I suspect it is a shorted convergence IC. It would be best to call a service center to repair the TV.