4x4x4 LED cube

[christinajane]

Hello,

Just wondering if anyone could help me trouble shoot this problem.

I am completely new to electronics and soldering and this is my very first project so I am a bit in the dark as to where to start looking for the problem!

Made the cube - more or less - its definitely not a geometrically perfect cube lets put it that way.

Anyway - plugged it in and it does light up. However, the whole top row and third row of led's dont come on with only the 2nd and fourth level working. There are two LED's in the corners of the working levels that don't light up either. Could this be the problem?

Thanks for your help

Chistina

[andrew]

I have replied to your original post on our blog site but for convenience i'll post it here:

There’s nothing particularly special about those two layers and the fact that the other to layers are working helps rule out a lot of possibilities so hopefully its something minor.

By not working do you mean none of the LEDs are not lighting or that they are not lighting in the expected pattern? Also is it running the default demo that’s pre-loaded into the cube or have you reprogrammed it?

[christinajane]

Hello,

Thanks for getting back to me.

At least its nothing major!

Ive plugged it back in and actually following the Led's it is only the first layer (top one) that is not lighting up AND seemingly none of the corner LED's, the ones to the right of where it is plugged into the USB lead.

Would this have anything to do with the wire attached to the top layer - maybe I haven't soldered it properly? Not sure why the corner ones are not working though..?

I haven't reprogrammed it no. It's running through the pre-installed programme.

Thanks for your help again.

Christina

[andrew]

Would this have anything to do with the wire attached to the top layer - maybe I haven't soldered it properly?

Yes this is the most likeliest cause of the problem. That wire is responsible for supplying power to the entire top layer of LEDs. So unless you have every LED on the top layer the wrong way around, which is unlikely as it looks like you've got them all the correct way on the lower layers, then that's the probably where the problem is. Just give it a check for a bad connection or bad solder joint. Also check that the pin circled in red in the image below is soldered correctly:

LED_Cube__Top_Layer_Pin.png

Not sure why the corner ones are not working though..?

For the 5mm LEDs on the corners, these are all independently powered from the 5V supply and should light the moment power is connected to the cube. For all of them to not work there would have to be 4 separate faults which is unlikely so my suspicion is you may have soldered the LEDs the wrong way around. There is a small flat side at the base the LED but its difficult to see. If you can find which side of the LED it is on it should face to the outside of the cube for each LED.