Guidance for working out issues is needed in your documentation & code

[mattcuk]

So my son and I soldered the kit together, but there are issues;

• Layer 3 (2nd from the bottom) doesn't light up
• The LEDs in vertical column 5, 17, and 27 don't light up

What's the best way to go about investigating/fixing this?

The wiki & assembly instructions don't give me any indication of which board pins & solder joints each layer goes through. And the same applies to the vertical columns powered by each pin.

I've inspected the soldered joints visually and can't spot anything obvious, so how do I go about diagnosing where the problem lies without a circuit diagram / schematic? Maybe there are points where I can put a multimeter probe, but without the schematics I've no idea where to position them.

I feel like a kit like this needs a bit more than just basic assembly instructions, especially when it's aimed at kids, where it's probably the first project they've attempted to put together.

I tested each LED before we assembled the layers into the cube, so I know they individually work.. even that should be in the guide so that people can sanity check the build before it's too late.

[sbcshop2]

Can you please share images of the cube you assembled and make sure each layer should be in ascending order from top to bottom (1-4 from top to bottom)? Also, carefully do visual inspections of it by making sure each and every 4 soldering pads of every joint are soldered properly and there are no break points. If you further need a schematic of it, we will share it. Thank you!

[misel228]

Schematics would be helpful either way because they provide information on where to check connections with a multimeter.

[mattcuk]

I've visually inspected every joint and they look ok (to my untrained eye). However, I could really do with help knowing how I'd check the 2 issues I detailed in my OP, i.e.

1. Layer 3 (2nd from the bottom) doesn't light up
2. The LEDs in vertical column 5, 17, and 27 don't light up

For (1), how would I go about checking this with a multimeter? The schematic should help here, since it'd show me what pin and soldering pads to specifically check for that layer, and if there was damage to a wire within a pylon, how I could use a spare bit of wire to jump between pads.

Same goes for (2).. if the pads look ok, I assume I can trace a path from the affected pin into the pylons & layers, checking the current flows through the board as expected.

I'll post some pics when I get back from work tonight, but I don't think you'll gleam much from the pictures.

[sbcshop2]

Hi Mattcuk,

Hope you are doing great!

We have uploaded the schematic of it you can check it out and let me know if it is helpful to your issue. Thank you

[misel228]

Thank you, @sbcshop2 , this certainly helps a lot.

@mattcuk since it's one whole layer and always the same LEDs in each layer it's likely that the corresponding Pico's GPIO pin is not properly connected to the base. That happened to me, too.

Have a look at this:

https://www.raspberrypi.com/documentation/microcontrollers/raspberry-pi-pico.html#pinout-and-design-files

Check the GP[X] pins where X is the Pin number also used in the code. (e.g. 8 for the second layer from the bottom).

[mattcuk]

That's great @sbcshop2 .. I'm now able to trace through from the pins & do a continuity test using a multimeter, looking for bad connections/joints.

Thanks @misel228, yeah, I'll trace that through and check. I'll do this with my son at the weekend so it helps with his knowledge of debugging problems like this :)