Update: I eventually managed to fix this! Turns out I just had a blown fuse located behind the charger port! All I had to do was either jump it (not recommended; the fuse exists for a reason), or simply desolder it and replace it with a new one. Unfortunately I’m not quite sure what fuse would be a suitable replacement, but if anyone has any info on this, feel free to let me know!
I was unable to find a replacement, so I took an orthodox approach; I soldered female pin headers to each of the 3 solder pads that the IO port would normally be soldered to and snipped off the end of my link cable, and soldered a male pin header to each of the 3 wires from the link cable. While this method was a bit hackish and certainly not the prettiest thing in the world, I am now able to connect my ti 83 plus to my computer by simply connecting the 3 female connectors to their corresponding male counterparts. EDIT: I eventually got the courage to give my calculator the repair it deserved. No more ugly wires coming out of the calculator!