My iphone 4 screen won't turn on, even after reset?

The common solution to a blackout-ed iphone screen is to reset it with the home button and the power button, but that wasn't the case for me. I've had water damage on my phone before, but it was fine after being submerged in rice; that was a few months ago. Today, my phone screen went black after a call, and so i tried resetting it. The Apple logo came on the screen, but after a few seconds of waiting, the screen simply went back again. I could receive calls, texts and etc. Again, i tried resetting: the same result came. I don't know what to do )

Try holding the circle button at the bottom and holding the power button at the top at the same time for 10-30 seconds

Take it seriously:

Get hair dryer, heat it hard for 5 minutes. I did it once, it worked.