Good evening. I bought a BOSCOM model M off ebay. The seller said the keyboard had been dropped and was for parts only. The only issue I have is that the left shift is sending key presses continuously. I opened it up, and I can't see anything obviously wrong. The only thing I haven't done is taken the heads off the rivets and looked at the printed circuit board. Is there anything that might cause this that doesn't involve the bolt mod? I'm good to do it, but I don't want to waste my time.
Looking at the PCB is probably the only to find out what is actually happening.
But it sounds like there is something bridging the contact, just stuck on on top of it.
Edit: Though I will point you to www.reddit.com/r/mechanicalkeybaords where there the issue might have come up before, and cleaning guides.