Black screen every two seconds?
So this morning I turned on my phone and opened the Skype app and opened a message, then the screen stayed black and then went straight onto my lock screen. I tired entering my password but it wouldn't respond. Then it turned black again.The screen kept turning black every 7 seconds. I took the battery out and turned my phone on. But the weird Samsung turn on screen repeated 3 times until I was at my lock screen again. This time I could unlock my phone, but only for about 4 seconds, then the black screen would return. I couldn't power it off, and taking all the Sims out didn't work. Now I've left my phone alone and every 7 seconds the black screen comes on and goes back to the lock screen, then black screen and keeps repeating.
How do I fix this?