I've been looking at the shield and cannot make sense of the traces. The big tab at the top of the AMS1117 is the output , which also attaches to the center on the bottom. The bottom right pin is the input, which appears to go to all the 5V pins, and back down towards the front to the diode/capacitors and input plug.
It could just be the angle distortion, but the general layout doesn't look correct. Can you track the input voltage from the connector? The pin on the back of the black housing is positive, and the side is negative.