My Samsung S4 does not fully boot. It turns off after two seconds after the Samsung screen and before the Cyanogen boot screen. How do I resolve this issue?
I can't boot into recovery -- it never gets that fair. I also can't reflash as the phone turns itself off shortly after it gets to the flash screen. The phone also randomly restarts. I've tried swapping the battery too.
This is the infamous power button problem. I had this too. There are some guides that speak of cleaning the power button, but for me I found this rather rough solution to be effective.
Alright guys, so I'm back -- it's 2016/04/25. My S5 just broke so I'm downgrading until it comes in the mail. Googling for the same problem and I found my own answer. This time hitting it hard didn't work. So I sprayed the button liberally with DeoxIT D5 and violla, back in business. Hold the phone button side up and just soak it!
I found the solution. The power button is stuck. Just flick the power button a bunch of times with your finger. If that doesn't work try compressed air, shoot that in there a bit, so it gets unstuck.
If you spilled soda in there maybe try getting an alcohol wipe and try to wipe it down a bit (make sure battery is off) maybe squeeze a very very small amount of rubbing alcohol in there. I mean very small amount, then wipe with Q tip. The flicking technique works for me every time.
Could be dust in there.
Try banging the corner where the power button is, on a hard rubber surface. Be careful not to crack the screen. Remove back of phone and battery first, of course. It worked for me.
I think this might be the power button that got stuck and need replacement.
Here's the link for troubleshooting and solutions. You might need some simple electrical skills. https://www.youtube.com/watch?v=2l_6fwzuIwA
