#331

So, unfortunately, I’m going to tell you to check a surprising number of connections:

  • check all the pins on the multiplexer chip (the big one). Are there any bridges? Are there any not correctly connected?
  • check all the pins on the eight op-amp chips; are any bridged, or not connected?
  • (most likely, being honest): check all the clusters of 5.6K and 10K resistors around the opamps - are any not correctly connected?

Multiple things moving at once might seem like a bridged pin on the mux, but can often be down to crosstalk coming from higher voltages creeping into the multiplexer - which means things not divided down correctly. So checking the voltage dividers will help.

I appreciate that that’s most of the board.

2 Likes
#332

Question, could some excess flux cause this type of problem too? I feel like maybe I used too much.

I will go through a process of clearing all flux away and then touching up all the ohm’s. I just looked and there are no bridges and the ohm’s honestly look like they’re properly placed. I’ll probably post pictures of the board here soon and see if maybe someone spots something I do not.

#333

Flux probably shouldn’t make much difference of itself: it mainly exists to make solder flow more easily, and solder shouldn’t flow over the mask on the board, but checking for bridges is still important.

My other suggestion would be to upload some nice well-lit pictures of your circuit board?

#334

Also check the fader solder points. Seems obvious, was the last thing I checked when I had fader issues… good luck.

#335

Here’s the front side for now:

image
00CED6D2-7EF1-43E6-B68E-906307BEC974.jpeg3024×4032 3.07 MB
image
8E93275D-4848-41E0-83CA-EA431B82AA36.jpeg3024×4032 2.98 MB
image
6546EE55-2529-4116-B4EB-A84DCE261A5C.jpeg3024×4032 2.79 MB
image
F2A114F0-B281-4BA4-ADF8-23E2868E5AFD.jpeg3024×4032 2.86 MB
image
21EFDFA6-C1A9-4C8D-99FB-24D4C9467C05.jpeg3024×4032 3.11 MB
image
37C04478-55C9-4ACF-8077-FE3C4E4A3731.jpeg3024×4032 3.5 MB

I will check (and sure up) the back side solder points, but on the front I don’t spot any bridges or issues with the resistors. They look a little ugly, since I went back to touched up all of them… but I’ve made sure and the 5k and 10k are all in the right spot (I will double check that again with the build materials).

I have a conference call that I will just be listening in on in 45 min, so that’ll be a good chance to touch up those back points and see if maybe the fader contact points are a bit faulty

The excess of Flux was from my making sure there were no bridges last night. Really made that stuff work for me! Gotta spend the time to clean it up.

#336

Is that flux on the IC’s? They look a little ‘melty’.

#337

Yeah, that’s flux. I left it on over night, so now it’s all gunky. I will be doing a more rigorous removal over the next hour

Just because I don’t actually know, the IC’s the chips?

#338

Yes, the chips. Integrated Circuit is what IC is short for.

1 Like
#339

I’m gonna clean them now, if I indeed burnt them, I’ve got quite a few extra.

It was flux, they look pristine when clean.

1 Like
#340

Retouched every slider contact point, cleaned up the flux and looked at all the contact points and haven’t seen any issues… Still getting the same noise…

#341

R37/38 look bridged, or messy, for sure, and could be tidied up.

Various IC pins look like they might be dry (not connected), eg this one on U9:

image
image.jpg735×662 153 KB

and these on U8:

image
image.jpg594×591 131 KB

and possibly these on U6:

image

If the pad under the pin doesn’t look like it’s got much solder on it, that might indicate a dry joint. You won’t need much more solder to fix this: just heat the pad and pin together and watch things flow as you tidy up.

#342

I’ll use a little more solder and see what I can do.

Summary

Okay! Fixing U9 has given me control over 15 and 16. This seems to be a big key. I’ll go through each of them and see what I can get back.

So, having retouched these, things are looking better. Sadly, sliders 3 and 4 are unresponsive… this is their U3 chip after the work I’ve done:

IMG_3896
IMG_3896.jpg3024×4032 1.86 MB
IMG_3897
IMG_3897.jpg3024×4032 2.03 MB

They get a little movement when I move 5 and 6, which means something is obviously going wrong there.

I have redone and added a bunch of extra solder to the points, this is now where I’m at doing each slider:

https://llllllll.co/uploads/default/original/3X/8/a/8ad063ea6b1b351e393a5d66bb75c494d281b1f0.mov

As a side option, I have more of the chips that go in the U2-9 slot. I could replace the one for sliders 3 through 7. The stuff that occurs at 10 is pretty odd thought. I’m not really sure how I goofed this one up so bad…

So, I’ve been getting stuff done and find that most issues are fixed. I still get an oddity when fader 10 is all the way up, and faders 3,4 are not sending anymore, but I believe I can fix that by cleaning up/resoldering the resistors and getting better connections on the mux. Thanks for the help

Okay! Having shirked my real world responsibilities, I have spent all day resoldering every resister. I am now fully up and running. I have yet to check the CV ports, but I’m mainly midi at the moment anyway.

Thanks for all the help and now that I understand this thing so much better, I will pay the knowledge forward.

1 Like
#343

glad you fixed it.

In your first photo - of U3 - R23 just isn’t connected at the right edge, and the right edge of R37 looked flaky. That will lead to funkiness for sure with the digital (midi, i2c) side of things.

#344

I have a question in regards to using the 16n with the norns. I am currently using it with my norns (for mlr) and I’m noticing that when I assign a fader to, say, overdub, when the slider is all the way up, I get to a value of about 0.95. They don’t get all the way to 1. Is this purposeful?

#345

this happened to me as well! what’s the best way to power the 16n other than the usb-c on the teensy?

#346

Does anyone have any tips regarding cases for transporting the 16n around? Any lucky fits? :slight_smile:
Been searching for this answer across lines but to no avail.

#347

both of these should work…

you can also look up “computer keyboard case” for some other solutions

1 Like
#348

awesome, the Glide case looks that it could do the job…

thanks! :v:

#350

Is there a Win 10 driver for the 16n as a MIDI Controller?

#351

You shouldn’t need any special drivers, it appears as a MIDI controller to Windows.

1 Like