Neopixel blade not working

[Rpg007]

This is my third neopixel build using TCSS neopixel strips (2) and the wiring setup posted by TCSS. I have wired and re-wired this setup and cannot get the blade to work in either of the other two sabers I built using the same setup. I replaced the PCB (even using a TCSS pre-soldered resistor just to be sure). Can anyone share how I can bench test the setup of the pcb to be sure the resistor is soldered correctly and that the LED strips are working?

I would add that as I write this, I realized that the LED strip is about 12 LEDS longer than either of the other two sabers, so do I need to tell the board a new length to test this longer blade?

Thanks in advance for any advice!

[Light Bringer]

Please post some pictures of what you have so we can better diagnose the problem. There is probably a wiring issue on one of the ends. Also tell us the setup (which soundboard, what battery setup, what size wires are you using, and what to you have the board configurations at?)

[Rpg007]

Thank you!!

The saber is a Crystal Focus Sound Module X (Oct 2019 purchase), using the DM Sony Li-Ion 18650 3.7V 15A 3120mAh PCB Protected Rechargeable Battery, 28 gauge wire, Wired up per https://www.thecustomsabershop.com/Pixel-Blades-C153.aspx.


The board is set up to run another blade that has 124 pixels, but this one has 137 for a hilt that is still under construction.17951

[ASCI Blue]

have you tried each strip separately? this may be a long shot but the first LED on each strip may be bad. if so the blade won't light, I ran into a similar problem on my blade and the first LED on one strip was dead, the other one lit up. removed the bad LED and it worked like a champ.

[Rpg007]

Good idea. I just desoldered each LED strip separately but still nothing for either one. Darn it! I will try cutting off the first LED on each strip and trying again. After that, I will remove the whole led strip from the foam and double check my work for a short or something. I will keep posting my results.

[Rpg007]

I tried removing the first LEDs on both strips with no luck on getting either to fire up individually or together. I did this twice just to be sure.
I inspected the entire strips and see no shorts or anything out of the ordinary - I taped the joint and the ends as per madcow video.
I reset one of my other hilts to match the number of LEDs - no effect.
I have two other blades built with the same method that are working in two hilts.

My instinct is telling me there is something up with the PCB and resistor but not sure how to confirm the resistor is seated. I resoldered it to be sure but no effect.
I just can't imagine the LED strips are both bad and I believe tested before shipping.

[Light Bringer]

Will you try something for me? If you have a higher gauge wire, try using that. Neopixels require quite a bit of power and 28gauge wire may not be thick enough to supply the power needed. Try using 26 or even 24 if you have it. I would be surprised if both strips were bad..... And I would be surprised if the pcb was problematic. Also verify that both strips are going in the right orientation. Both strips should have the arrow pointing towards the top of the blade.

[Strydur]

28 gauge wire is for sure not large enough for neopixel. Use 24 gauge.. That is probably not the problem at the moment since it does not work at all but once it did work it probably would have melted those wires.

[Tom Tilmon]

Data. Without a data signal, neopixels won't light at all. Improper wire gauge will make them dimly lit, but even with thin wire gauge, they will still light up, IF THEY HAVE DATA and Power.

You can test the strips with a spare soundboard or a neopixel controller. You can get cheap neopixel controllers from amazon to test your strips. I think you need to first get your strips up and running, so you can start isolating and diagnosing the problem. You could have a bad solder on the 0603 resistor in the blade pcb. If you have a multimeter, you can measure resistance across the resistor. You can then put one probe on bullseye of the target, and the other where your data line connects. You should be reading the resistance you get going across the resistor. My guess is that you have bad data continuity somehow, either a bad/broken 0603 resistor, or bad joint on the resistor. Need a multimeter to diagnose. Make sure to select the appropriate range for the resistor. 330-500, so the range needs to be higher than that to measure the resistance.

Tom

[Rpg007]

So I got back to it tonight. A test of the resistor and visual inspection showed it was obvious that the resistor was the source of the problem. I replaced it and voila. I also changed the wiring out to 22 gauge.

[Tom Tilmon]

So I got back to it tonight. A test of the resistor and visual inspection showed it was obvious that the resistor was the source of the problem. I replaced it and voila. I also changed the wiring out to 22 gauge.

Glad you got it sorted. Data is often a culprit.