iphone 5 has a blank screen

i am going really crazy right now because my iphone 5 has a blank black screen and when I push the home button it does not turn on but when I hold in the home button siri comes on and when I call it it rings but the screen doesn't come on and I cant try to turn it off because my power button is broken I had this happen before but after like 5 minutes it would work ive been trying to turn it off for the past 30 minutes.