my phone just turn off and I cannot turn it on. what can i do to fix it

Try resetting it:

Press the Sleep/Wake button & Home button at the same time, keep pressing until you see the Apple logo, then release.

In addition, you might also review this knowledge base article.

I know you said that it is fully charged, but just try plugging it in if none of the other options help.

My friend has had the same problem as you after dropping her phone. It just turns off and won't turn back on unless she plugs it into the charger.

My lock button on top wont work. Now, I can use Assistive touch to lock and shut it off, but how would I turn it back on? Could I just use the home button to turn it back on? I dont want to try it and have my phone shut off without being able to turn it back on again.

Thank you, my phone hasn't been working for a while!

thos solution did not work, any more suggestion??

This used to work for me before but this time , nothing!!!