My hitachi turns on and says no sync no signal

Hiya!
If I understand your question, it seems that you'll need to go into the TVs 'input selection' part of the menu and try another input until you get a signal
Please let me know how it goes

It's not the tv's problem. Broadcasters sometimes transmit out of sync programming. Cable company equipment also contributes to the problem. OFF air isn't immune to digital sync problems either.

It could be the lamp---if you remove the lamp look to see if it is shattered inside---average life on lamp is 2,000 hours or 2 years.

I'm watching live TV or recorded TV and it flashes up with a black screen saying "no sync signal".......turn TV off and then on and its all ok??????? anyone?????

Tries tv and those pay boxes unplug,replug it back like about an hour later.By letting the tv resetting itself back to the factory setting.Those pay boxes,now will be rebooting and upgrading it softwares.The incomming broadcasting signal sync problems should be solved,if still have no sync signal flashing,than 90-95% those pay boxes have a problems.Call ur cables providers exchange the reciever box.

you are not getting a signal change soure ie box or dvd player and input jack then try

The Main digital board has problem, part# UX28023 (for P42H401, not P42H401A) , approx $170.

YOU ARE GETTING NO SIGNAL INTO THE UNIT, THE PROBLEM IS NOT THE TV

Might be the digital board, which on this unit you're in luck, easy to diagnose. The digital board has a group of led lights on it D302, D303, D304, D305, D306 if when you attempt to power up and of these begin flashing or changing colors it's likely digital board needs to be replaced...
If any of this sounds to foreign get a pro on this, you can mess this unit up in the blink of an eye...
Bill

hold down your playstation button for a few moments and it will automatically sync to the tv at optimal settings. And thatz wut it doobi