u/Fine-Heron5439

Hi everyone,

I'm hoping someone here might have ideas, or maybe even knows a repair place / hobbyist near Deventer or Rijssen (Netherlands) who could take a look.

I bought a Lily58 Pro second-hand from another Reddit user a while ago, and it worked absolutely perfectly for quite some time.

Recently, a few accidental TRRS cable disconnects happened while the keyboard was powered. Since then, the split functionality stopped working.

Current symptoms:

• Left half via USB-C → left works perfectly, right OLED powers on but right half gives no input
• Right half via USB-C → right works perfectly, left OLED powers on but left half gives no input
• Both halves work fully standalone when directly connected via USB
• OLEDs still receive power
• Tried multiple TRRS cables
• Reflashed firmware multiple times (QMK, RP2040 conversion build, serial split transport, different serial pins) with help from AI tooling, no improvement
• Continuity-tested the TRRS cable and jack with a multimeter and didn't find obvious issues
• Split communication simply never comes back

Hardware:

• Lily58 Pro
• RP2040 controllers on both halves
• OLED displays
• Originally using Vial/QMK

At this point I'm starting to suspect hardware damage (TRRS data line, GPIO, trace issue, solder joint, etc.), but I'm still relatively new to keyboard electronics.

Does this sound familiar to anyone? Any obvious things I'm missing?

And if by chance someone is near Deventer / Rijssen in the Netherlands and would be willing to take a look (or knows a local repair place/company), I'd really appreciate it.

Also, if anyone has useful troubleshooting tips, tutorials, repair guides, or debugging ideas, those would be very welcome too — local help is appreciated, but advice from anywhere would help a lot as well.

Thanks!