Iconia Tab A500 Not Powering On

It looks like a few days outside of the warranty period for this tablet, the screen doesn't come on at all. The power button does light up when I plug in a charger and if I remove the charger and hold the power key for a few seconds that power button light will come on and stay on. Then if I hold the power button for a few seconds again it will go off, but there is never any indication on the screen nor any vibration from the device.

If I shake the device a little I can hear a faint rattle near the camera lens, although I can't be sure it's not just the vibration device. Taking off the back cover I found the small green board right by the charging port was loose and not secured to anything. I checked around for screws or holes and found none, and then saw there was a sticky residue underneath the board so stuck it back to the metal plate underneath.There is nothing else that jumps out at me as incorrect. 

Here's what I've tried so far to troubleshoot:

• Using a different charger
• Resetting with the volume buttons
• Hard resetting by inserting a pin into the reset button and holding it for 10 seconds and then pressing the power button for 10 seconds
• Using a mini hdmi cable to check if the screen outputs on a monitor (it does not)