Hi, can anyone help with Iphone 4, is stuck on Connect to iTunes

What I need to do, if is showing on Iphone 4 - Connect to iTunes

1.What I did conect to itunes then come up mesage:

There is a problem with your iPhone.

Please visit theService Answer Centerto find answers to all your questions about service options, warranty and other processes in your country.

To find your nearest Apple Store,click here.

2. I visited the apple store and they try restore the iphone and hapend but nothing changed is come up again the message.

So one man from enginering take a phone for check and he sai that may be is been replaced the sreen and is not from apple brand, so may be for that reson is showing mesage.

3. I open the phone and take out main board and put to good working phone. So what hapeand? same thing, same mesage come up. Never mind, I conect to itunes and hold button with power buton to restore phone again, but nothing changed same mesage on itunes.

4. I check the IMEII if is blocked or no and is unblocked.

Can anyone help with this issue?

Thanks