S3 functionality (no LCD)

I’m almost there! I have a quick question about button S3, and I don’t have my LCD on yet, and I didn’t find the answer in the reference manual.

What is the correct behavior of this button at startup? Sometimes when I press the button, the LEDs will switch back and forth very quickly. Do I have a short?

Thanks again for you help!

S3 switches between the two LFO / Envelopes pages. First press : L4 is lit. Second press : L5. Third press : L4. Fourth press : L5… and so on. If the LED lights up very shortly, there might be a soldering problem on:

  • The resistor network
  • The switch S3 itself
  • The 74hc165

Thanks for the guidance, Olivier. At least now I where to start troubleshooting.

The problem only occurs about one out of sixty button pushes, but I wanna get it fixed if I can.