I built a SP-111 (mill-maxed pcb) about a month ago and it was working fine, but it recently starting behaving abnormally and I can't seem to figure out why (pcb has stayed in the case/ no spills etc). When I plug in that right pcb half, it presses down a column of keys and holds them down. I can see them being pressed in via and any text input I am focused on will be spammed with one of the keys. I have tried reflashing the pcb halves and removing the affected key's millmax sockets. At the recommendation of BlindAssassin, I have looked for scratches in the traces, but can't find any. I have also removed the stabilizers and band-aid mod, but it has no impact. The specific behavior is that all the keys in the column: F8, 9, i, k, m and right space are all being triggered at once.
Any help with this issue would be much appreciated! Am also willing to get a multimeter to debug this if someone can recommend one.