LCD Wont Work/Flashlight Turns On When Power Button Is Pressed

I have a customer that asked me to repair his screen. I ordered a screen and tore the phone apart like always. In doing so, I found the first part I originally ordered didn't function correctly. I returned that part and ordered from a new source. I didn't bother replacing the phones screen with the original broken one so I wrapped it in microfiber towel to keep from any contamination.

I've finally received the new part after a week of waiting. I plugged the LCD cable into the pins that it matched. I turned the phone on and it vibrated. That obviously indicates that it's still functioning. I waited for a moment or so and the LCD didn't light up. Keeping the battery in, I tried removing the ribbon cable from it's pin match-up and received a flash from the LCD with the Samsung logo for a moment. After that moment, it went black again.

After trying to re-seat the cable multiple times, I'm now greeted with the flashlight flicking on when I press the power button and I don't receive the "power-on" vibration anymore. I've checked the board and made sure everything is where it's to be. I've also re-screwed the board to the phone thinking it was a pressure problem. I was wrong.

I've been working with this phone for hours now and haven't found the problem. Any ideas, people? I need some help.

Thanks!

-Nathan K.