Control board test problem

OK… So I’ve just put together the control board and tried out a first test and… It doesn’t seem to be working properly! I get LEDs 1, 2, 4, 6, 7, 8 lit up but nothing on 3 and 5. And certainly not just 3 and 7 lit up. What have I done wrong?

That sounds very strange…

Could you please post a photo of your assembled control board (both sides)?

OK… here it is . And do excuse the wretched soldering technique. I wish I could blame the soldering iron. But I think it’s me.

First: R16 and R15? (2k2, red, red, black, brown)

And have you check the orientation of RN1?

Doh! I’m a fool! I’ve missed R16 and R15. The orientation of RN1 is correct.
I’ll fix R16/15 and see how it goes.

OK… That’s an improvement. I think. Now when I power on I have just LED 7. Still nothing on 3. But it does now respond to turning the encoder and pressing the switches (it didn’t before). Still not quite right though, is it?

It seems you have a cold solder joint on the 3rd resistor linked to Led 3. (Hard to tell with the picture).
Have you assembled the filter board? If yes, could you try to send midi notes and listen to the output?

No filter board yet, I’m afraid - not on this Shruthi - I could try swapping one out from another though… You’re probably right about the third LED resistor - I’ll try re-soldering that first.

Nope, still nothing on LED 3 or 5

Ok, it would have been too easy.
How are you powering the control board if you have not assembled the filter board?

5v power supply to +5 and ground

Ok. I tried to check the picture again. cannot check precisely for solder bridges.
My expertise cannot go further than that. So check for solder bridges (Pin 2 of IC3 74hc165?) as said on the troubleshooting section around IC3.

OK I’ll do that. If no luck soon, I’ll try again tomorrow; it’s getting late here. Thanks for your help

No solder bridges around IC3 that I can spot. I was wondering if there were a couple of joints aroubd the DIL40 socket that I should tidy up but that shouldn’t cause the problem I’m having now should ut?

It never hurts to touch up any solder joints that look iffy. All of them have to work before the PCB is OK at any rate.