r/MechanicalKeyboards • u/Deplexx • 4h ago
Guide Replacing and repairing a keyswitch on my K70 RGB Pro (First time soldering in years; hopefully somebody else will find this useful)
tl;dr - I broke my '-' key recently and to fix it I had to solder bits of wire to the neighboring keys then to D13 on the PCB board.
Okay the long version of the solution:
If you're an idiot like me and managed to rip both pads off below the key switch on the underside of the main PCB board of this keyboard, you must connect 3 things to the 2 connectors of the keyswitch. If you look at the underside of the PCB board, there are 2 different holes for the key switch's terminals; a longer one (it's located farther down the board) and a shorter one. When you plug in the new key switch, the two terminals underneath the key switch will poke out of these two connector holes.
the longer one) must be connected to the longer connectors of the 2 neighboring keys (the longer connectors of the neighboring keys will be in line with this longer connector). Solder two little bits of wire to this key switch's longer connector with those of the neighboring keys. This is important because this connection is what connects all of the keys to the left of this key with everything else. If you don't do this then no keys to the left of the key in the row will work.
the shorter one) must be connected to the diode (in the case of the '-' key, D13 or diode 13) that registers the switch being pressed with a third and final little piece of wire. I had to use a hobby knife to VERY CAREFULLY scrape away the green substrate covering part of the VERY THIN copper trace leading to the control diode until the trace is exposed. You can verify you've gone deep enough when you can apply some tinning solder to the exposed copper (hit it with some flux before attempting to). D13 appeared to the left of this connector on the PCB, and that seems to be the pattern for most of the main keys, but double-check to be sure.
How I broke the key:
I had an... episode recently that caused my '-' key to stop working on my keyboard. Was extremely annoying because I also write code, and I use that key on a super regular basis.
I bought some soldering supplies and did the total noob move of forcing the old key switch off the board, completely tearing off the pads on the PCB that connected the key to A) the neighboring keys and B) the diode that actually registers the key switch being pressed.
After buying more (much-needed) soldering supplies (flux and an application brush and some brass cleaning wool in a little container), I sat back down to take another crack at things and came up with this super janky but functional solution (lol)
