A day of dumbarsey… I wanted a stereo VU for my effects rack and the parts arrived today so I got started. I bought 4 displays and 4 lm3914 chips. Tested a couple of the displays for polarity and blew the LEDs. Two left, no problems. Built the schematics and tested, completely dead, power shorted, I had wired the +5v to ground instead of the pin next door. Fixed that, still not much happening. Looked around the board and measured some resistors, seems I mixed up the 4.7k and 470r resistors on both sides. Swapped them around, one channel works but the LEDs are not in a line. Second channel had a bad solder joint from the input amp to the lm3914 chip, rejoined and both channels working, but LEDs still weird, LED 1 ok, LEDs 2-10 reverse order, had to rewire 18 connections into the right order, now it works.
Glad it works, wow, I’ve had days like that, not fun!
Hmm, should this not be a constant current supply if it is meant for LEDs ?!
iam not even going to mention my PCB for a works thing…
Well
Last year I did a Quix forour department winther catchup. it was a fastest finger style quiz, with stripboad and 3rd party module technology… and generaly worked. after the event I decided to productionise the hardware but fell by the wayside…
Last week, volunteeered again.
proper look at the hardware ( v0.0.2) already as i Identified a stupid mechanical issue on the pCB. I was using PORT write command to access a MP3 module in a FAST way… But turns out whatever documentaon I had read , was totaly wrong for the arduiono PORT asssignment… So that was NEW PCB time…
But, and it’s not my fault, I was bread boarding the MP3 to test, and getting no result… Thiungs were failing arround me… turned out the breadboard power adapter was regulating at 8v not the advertised 5 
…
Rob
That i dont know, they are labeled as 24v constant voltage but I’ll know for sure once it’s on the slab and I’ve had a good rumage around.
Remember kids, always make sure your board inter-connects are the right way around.
And if you misspell your flags in KiCad, connections will not be made.
I noticed the first one before I started soldering. That second one took me an embarrassing amount of troubleshooting to find.
Well, if it works, who cares…
yeah you see that kind of thing on " factory " built stuff occasionally.
7 bands is enough for anybody.
made me smile that one…
Wonderful! I bet they’d fit vertically 
These may help you…
Yeah these are not cheap, but they are soft touch.
got a bag of those laying around some were it wasn’t for this project but same problem .
this is what I did for mine . these are from a Halloween costume necklace I drilled them from the back .
the most beautiful of all !!!
Why is everything but my trigger working. Why is everything but my trigger working. Why is everything but my trigger working. Why is everything but my trigger working.
One of these diodes is not meant to be like all the others.
… yup. Switch that diode around… such a nice envelope generator when it works.
I called the new PCB design good to go. Then I changed it. Then I called it good to go. Then I changed it. Then I called it good to go. Then I changed it. Then I called it good to go. Should be safe to place the fab order sometime in 2029.