A whole column dropping out (U/J/M/Space) is almost always a hardware connection issue on that half (less commonly firmware). Since it’s only those 4 keys, focus on the column circuit for that side.
1) Quick switch/socket checks (fastest)
Pull one of the dead switches and inspect for bent pins(common on hotswap). Straighten and reinsert.
If hotswap: flip the board over and check the hotswap socket for that key—sometimes the gold contacts get pushed flat. Gently bend them so they press against the switch legs.
Swap in a known-good switch to rule out a bad switch.
### 2) Reseat the controller (if you used hotswap headers) If your nice!nano is socketed (EZ-solder/no-solder/Mill-Max), power off, remove the nice!nano, and reseat it firmly. A slightly loose pin can take out an entire row/column.
3) Inspect/reflow the column pin solder joints
A whole column maps to one nice!nano GPIO pin. If that pin’s joint cracked/was marginal, the column can “randomly” stop.
Use the pinout diagram for your board to find the exact pin:
Reflow the solder on that pin on both sides(header-to-PCB and header-to-nice!nano if applicable).
### 4) Check for a short With power off, look for solder bridges around the header pins for that column.
If you tell me Corne or Lily58, and whether you used hotswap headers or soldered headers, I can point you to the most likely pin/joint to inspect. Reply here or tag me so I see it.
If you're running into issues with your keyboard, check out our Troubleshooting page for common issues and solutions. If you're still having trouble, please reach out to use on Discord!
If you're running into issues with your keyboard, check out our Troubleshooting page for common issues and solutions. If you're still having trouble, please reach out to use on Discord!