Why my iphone 5s screen turns off ?

[iMore Question]

hello, I have iphone 5s for the last 2 years it was ok until one month ago when the screen started to turn off suddenly then after hours it goes back on all of a sudden ...
the touch is intact even when the screen is black I can answer calls by sliding on the usual place to answer a call, the sound and vibration are also intact even when the screen is black ..
the problem usually lasts from one hour to 24 hours then the screen goes on and everything is ok for a couple of hours ..
note: I changed the old battery to a new one, updated the software but no improvement !

 

[Rob Phillips]

Welcome to iMore! You could try restoring and setting up as a new device just to weed out any possible software issue but I sounds like way more of a hardware to me. I'm no expert when it comes to iPhone internals so I'm not 100% sure what your options would be aside from buying a new phone, contacting Apple Support or bringing your iPhone into an Apple Store or repair shop.