Motherboard screen connector issue

I recently swapped out the entire back housing and screen of my iPhone 5. After a few days the screen started failing. A week later it died completely. I thought it was a faulty screen, so I ordered a new one. Only to find out it wasn't the screen that was the problem. I tried both of the screen displays on another device - and they worked completely fine. My theory is that the LCD connector on the motherboard has failed. I have looked closely at it, but haven't been able to spot any physical damage. The device itself boots up without any issues - but I don't have any reaction from the screen what so ever. Does anyone know where I can send my phone in for some troubleshooting and possible repair? Thanks!