Screen turns on then turns off post screen replacement

I replaced the screen on my son's iPad mini 4 and I've had nothing but issues since. The screen will turn on for 5-20 seconds then go black but it's not like the screen turned off, I can still see light on the side of the LCD. To turn the screen back on I have to press the sleep wake button twice, once to turn the screen off then again to bring up the screen where you have to press the home button to enter a password. I have also replaced the sleep wake sensor as well. I was very careful when I took everything apart, I always disconnected the battery before I removed the screen and digitizer. I've forced restated it (home and sleep wake button) and factory restarted it as well in iTunes. I was very delicate with the screens as I handled them to avoid damaging the ribbon connectors. Has anyone seen this before or have any tips? I'm not trying to open a business, I was just trying to save some money and do the repair myself.