Case power LED stays on after shutdown
So I have an ITX system with these components:
Node 304 Case
HDPlex 200W DCATX nano PSU
Debian is installed in the system and whenever I shut down the machine, the power LED stays on for a few seconds until it dies out. It looks like there is capacitor residual charge somewhere and this is the first time I've encountered it in the case power LED. Here's a video of it happening: https://www.dropbox.com/s/yxeflv4xvc...95822.mp4?dl=0
So which is potentially the problem here? The board, PSU, or case?