Iphone wont turn on Black screen?

I was in the middle of my game and it just faded to black. I tried restarting it, DFU mode, hold home + power for 10 seconds.tried plugging into itunes, but computer doesnt recognize it. Please note my IPhone is jailbroken. It doesn't get stuck in the apple logo like most peoples. It's just plain black screen.

"… My IPhone is jailbroken. It doesn't get stuck in the apple logo like most peoples… " No, it just doesn't work anymore. Out of the blue bricking is an inherent risk of jailbreaking.