Why does my phone do this?

[AC Question]

I have a Samsung Galaxy Avant and it has been acting strange. It keeps turning on and off by itself. As soon as I insert the battery the phone automatically turns itself on. Sometimes it will turn off in the middle of the boot process and then turn on again. When it finally does boot up the power off menu shows up (the one that appears when you long press the power button) and then i press the back button. The menu will repeatedly show up as i try my best to close the menu until eventually the phone just shuts off and repeats the same cycle as before. My phone's warranty is over and I cannot afford a new phone at the moment. Is there a way to fix this problem?

 

[B. Diddy]

Welcome to Android Central! Offhand, I'd suspect a problem with the Power button, such that it's stuck in a pressed position somehow (either physically or electronically). You probably would have to bring the phone to a repair shop to check.