My iPhone 5S is stuck on a black screen but with a light on, how can I get this working?

[iMore Question]

iPhone 5S Stuck On A Black Screen But With Light?

I bought my iPhone 5s used on eBay and a couple weeks after having the phone, it would shut off randomly. It wouldn't bother me much so I didn't do anything about it. But not that long ago, my iPhone completely shut off and it won't turn on. I've tried the whole reset routine and I've tried connecting it to iTunes but it would tell me that "an unknown error occurred". Please help?

 

[kch50428]

Re: iPhone 5S Stuck On A Black Screen But With Light?

I would refer to qualified service personnel.