Camera Screen black, phone gets hot, and makes a weird noise.

So I've repaired plenty of iPhone 5 screens, and this time it was no bueno. After I replaced the screen, the cameras and LED stopped working altogether. I also noticed the phone gets hot in the back camera area. Experiencing rapid battery drain - we're talking 15% in 5 minutes just on standby. I replaced the front facing camera, still no luck. I held the phone up to my ear(around the back camera area) and it sounds like the motherboard is continuously trying to work. It's kind of hard to explain. Any suggestions? This customer is waiting for a solution and I'm hoping I don't have to purchase a new logic board for it.... :(