Iphone 5s can't Update because of BlackScreen

I upgraded my Iphone 5s to ios 11.4.1, from that time my phone started to restart, boot loop, and black screen. Sometimes it is working, but after an hour it's restarting and continuing to black screen. I decided to restore and update it. I made it, but still the same. Now, I can't update or restore because every time I put the phone to DFU mode, my phone is not responding from the update after extracting the Software that I downloaded.

I tried to "hard reset" but it did'nt work. What is really the problem? Is it the OS or the Hardware inside my phone?

Need help guys! Thank you!