V2+ Controllers not working

Hello there,
I decided to open up a new thread for a different problem I have with the build from this thread .

So I have the entire v2+ kit assembled, only the the audio-in jack is missing but that is for later.
I can boot up the zynthian correctly and use the entire interface, but the controllers aren’t working. Pushing, turning, it all has no effect on each 4 of them. Everything else does work afaik (audio/midi). My first guess is that it ain’ t connected to the controllers themselves but to the JST connector. My mainboard looks like the one in the wiki, http://wiki.zynthian.org/images/6/69/IMG_1277.JPG

But there’ s something not right. The JST-connector attaches on the mainboard only very loosely to the pins. Did I maybe solder it in upside-down?
Other things I inspected:

  • I re-checked through webconf if I’m using the correct hardware config plus did an upgrade. V2+ is selected. Even checked other versions (V2,V3) to see if it works, no hope.
  • Obviously I checked the solder connections of the encoders, but they look fine. Also it be more likely to have one or two encoders not working instead of all 4.

Just for completion, here also some images of one of the encoders. They all look the same way

Look likes the pins are upside down so they don’t go deep enough into the cable for contact on the All-in-one .

Probably a good idea to get some solder wick to desolder the pins followed by a solder sucker.
It will take a bit of work with all those pins. You may need a new 40 pin connector.

Also on your encoder pcb’s its a good idea to bend down and solder the tabs of the encoders.

And on the 2nd picture of your encoder there seems to be a cold solder joint on the top left. (May look good on the bottom of the board but also should have no gaps in the thru-hole on the top.) I’d also use nippers and trim the pins on the bottom. this is why the white connectors are bent down a little from the Capacitor pins.

The connectors are
Have you cutted the pins from the encoders? Also, you can try to bend the connector a little bit for allowing the connector to enter completly in the socket.

Anyway, you could check the continuity with a multimeter to be sure …

BTW, could you send a good photo of your AllInOne reverse side? Perhaps you pull the JST connector pins while soldering. The melted tin has a big surface tension and sometimes, if you are not fast enough when soldering, you can “pull” the pin with the solder iron…

In that case, you could try to push the pulled pins with the solder iron again :wink:


Thanks for your long and detailed reply. So probably my worst suspicions have become true and I have to desolder that entire connector

Is that needed only for better attachment of the pot? I tried cutting the pins with nippers before but didn’ t get them much shorter. Might need a better tool. Thanks for the observation on the cold solder joint.

@jofemodo thanks for giving me some hope and more insight.


Sorry, are you referring to the jst connector now or the encoder?

Will do ASAP

I really hope for that as desoldering every single pin will be tough work and might render the connector useless afterwards. Hope frustration won’t catch on to me too much!

Yes for better attachment. Angled nippers are your friend.

The connectors seem to be right. You don’t need to desolder. Check the images from the Wiki tutorial:


I mean the JST connectors from the controllers (encoders).


So here a picture from the bottom

And from the side
I’m (positively) surprised you mentioning I wouldn’t need to desolder. The pins are clearly the shorter one’ s sticking out on top. And the cable attaches indeed very loosely, almost hard to keep in . You sure? :slight_smile:

Ohhhh! Shit!! You solder the 40 rowpin connector (no the JST ones! the JST connectors have a white cap around :wink: ) upside down. It’s very difficult to desolder this connector, my friend. You can try it, but i never ever tried …

Probably you have to rebuild the AllInOne from scratch… in such a case, i will give you a very special price, OK? I don’t want you wasting your money, and i don’t need to earn money twice with your zynthian … :wink:


That may be needed :frowning: PM sent!

The other way would be to remove as much solder as you can with solder wick, Then use a heat gun. on the underside. Perhaps wrapping tin foil around the midi connectors to protect them.
After the connector is out, use a sucker…

Since your board might end up as scrap anyways, here’s one thing you can try while waiting for the replacement order:
On the solder side, put your soldering iron on one pin at a time. Wait. The plastic holding the individual pin will soften up pretty quickly, 10 seconds may suffice. Now push down on the pin with your soldering iron. That way you can move each individual pin towards the other side. I’ve done it before, it’s easier than unsoldering.

Good luck.

It is possible to desolder but as previously described may prove challenging and frustrating. @zynthicer makes a good suggestion of sacrificing the connector by pushing the pins out but I would first try desoldering. Try to ensure each pin is lose in the hole and don’t spend too much time on one pin. If it is awkward, move onto the next and return later. Use flux, e.g. fresh solder to help flow. Also protect sensitive components, ideally by removing and remember that the PCB track is likely to lift and be damaged with too much prolonged heat.

I have managed this several times but it is seldom easy and I have decades of experience.

Good luck.

Just to clarify…I didn’t mean to push out the pins completely. Just move them a few millimeters to the other side so that the ribbon connector makes good contact :slightly_smiling_face:

Holy $%!@ christ in nymphomaniac heaven, I used the @zynthicer technique and it worked!!! Thanks man!
Quite tough cause you need to get all the pins aligned on the same height at the other side of the board. 2nd time I solder something together, biggest adventure so far. Feeling grateful for the efforts of this community here :slight_smile:

1 Like

Congratulations :partying_face::partying_face: …and yes, it’s tricky to achieve even height. If you have a rather wide, flat tip on your soldering iron (covering two pins at once), it helps since you can always use the previously sunk pin as a stop to the one you’re working on. :+1:

Aaah gratitude. Perhaps a small audio contribution would release you of that weighty feeling? :face_with_monocle:

1 Like

Ohhh! Your are back, my lord!! …