iPhone 5 screen replacement; screen goes black after removing SIM card

Ive replace many iphone 5/5C/5S screens but this one has me stumped. After replacing a screen on an iPhone 5 everything works and functions as it should. No problems. After removing the SIM card tray, and reinserting it, the screen quickly goes black. The back light is still on and can hear notifications, messages etc. Ive done soft restarts and reopening the device to check the connections and even popped the cables up again and reseated them. After doing so, the same thing happens. Everything works until the SIM card tray is removed and reinserted. Any ideas?!!!

Thanks