my samsung galaxy s3 GT-19300 has no display

my phone has no display just a plan black screen. audio, vibration and the little LED that flashes at the top works fine i tried all the tricks on youtube and i still get nothing.
its probably due to the fact that my phone is cracked quite badly but there could be a possibility that i isn't and i was wondering if anyone has any ideas of what to do and how to repair it. I would take it down the repair store but its way to expensive for my liking! Can anyone help?

Sadly the repair shop is the next option, there isn't much we can suggest in terms of fixing it.