Black screen even after screen replacement and iOS repair

Hello,

My screen went black while video chatting on google hangouts. The sound continued to work through the call and when plugging in/using the vibrate switch. I let the phone die and tried plugging it back in to charge with no luck. My home button had previously stopped working and I was using the accessibility function to unlock before this happened, so I couldn't hard restart the phone. After some time I tried replacing the home button so I could perform the hard restart with no luck. I then tried to replace the LCD screen (including new camera, home button, etc). And have still had no luck. I tried replacing the firmware in an irepair software, and have now tried factory reset through the program and have successfully seen the phone get wiped (which has really defeated the purpose of me trying to fix it because I only wanted the data off but since the screen doesn't work I couldn't retrieve anything). I was hoping a factory reset would help and I could restore from an older backup and at least get some files back. iTunes recognizes the phone, I see nothing on it, the software has been updated successfully, but the screen remains black. The sounds still work as always. Is there anything else I can do or is this beyon DIY repairs? I live overseas and although there is an Apple store nearby I'm not sure it will help as this is a US phone, and it's way beyond warranty anyway.