Red color missing for the superflux led

97db38f2fd7964f4

Hi,
I just finished building the LoopA and currently testing. I have 3 superflux led that doesn’t light red. I have validated the path up the SN74HC595 and in test mode all other colors light up including the white. I can also light up the red if I bring direct power to the pin. I am out of ideas for finding the issue. Any suggestions?

Are there schematics of the PCB available?

17703227d9536da1

Please show a photo of your base PCB (both sides) and note the LEDs and I can point you to the right place.

The red superflux dies are sensitive to excess heat, but if you can light them up with a multimeter, then either a resistor, driver or shift register is not soldered properly.

Best,
Andy

97db38f2fd7964f4

Hi, thanks for the help but I just realized that I would have to dismount the keys to get to the back of the board where the problem lies probably. I leave it as-is. The impact is minor. Next time, I’ll be more thorough in my testing!

17703227d9536da1

All good! You might still be able to touch up the drivers on the back of the base PCB, but you’re right: if it’s a mis-soldered shift register, all of the Matias keys have to come off first.

Best,
Andy