iPhone unable to charge (After Replacement of Speaker and Home Button)

I've just replaced the home button and the speaker enclosure for my iPhone and reassembled it all back.

After the repair, the iPhone is unable to turn on. The battery seemed flat so I tried to charge it and it'll display the "exhausted battery" icon, proceed to the apple logo, and turn itself back off after several seconds.

I've replugged it in again and left it on charge for another 15 mins but still get the same results each time I repeat the process

Any ideas of which affected components may have contributed to this issue? (possibly a misconfiguration (mismatched screws?) or was any of the components damaged during repair?)

(I've tried a power cycle, no results and I've tried reassembling the whole thing again, still same issue)