apple logo the off then the apple logo is on again, then off

Hi, I have the same problem. It turns on and has the apple logo the off then the apple logo is on again, then off. And keeps on repeating that for 2 days now. I tried every single solution and reset but it doesn't work. I'm all ears but im pretty sure that i tried it.

How it happened : I was staying up late watching tv. While that I went over to my iphone 4 and updated it to ios 6. something. Then I walked away to watched tv then walked back while it was on the apple logo. I thought it was normal. So I slept and thought it was updating overnight. When I got up in the morning. It was still like the night. Logo on. LOGO OFF.

- A iPhone user. And was accidentally well. not accidently but relative passed down and was jailbroken.