Encoder issue - replace part?

I’m brand new to Zynthian and just received my kit yesterday. Must say I’m really impressed and excited for all it has to offer.

One of my encoders is malfunctioning and I need a sanity check before I do anything about it. The rotary action works fine on all four, but the problem encoder does not respond to a press action.

After noticing this, I swapped two of the encoders (kept the cables in place) and the issue traveled with the encoder. Not sure if this was an assembly error or just a bad component - I was careful to support behind the PCB when installting the knobs, but they were a super tight fit and I wonder if it was damaged in the process.

Anyway I think I know what needs to be done. Based on the specs here would replacing this component on the controller PCB likely be sufficient? Or could the issue be somewhere else?

Thanks in advance.

Hi @plimptm! Welcome to the wonderful world of Zynthian. I hope you will find the community to be a welcoming bunch.

Your initial fault finding was good. It sounds like an issue with the encoder. The next thing to check is whether the connector on the encoder is damaged. If you disconnect it and look into the connector you will see some pins. It sometimes occurs that pins get bent and do not mate properly. This can often be resolved by carefully straightening the pin, i.e. by inserting a small flat bladed screwdriver and gently easing the pin back into position.

Another issue may be a dry joint which is when a component looks to be correctly soldered but in fact is not electrically connected (due to flux forming an isolation between the pin and the PCB). This may be resolved by reflowing the solder. This involves heating the joint with a soldering iron and applying some fresh solder. Of course this is a more engineering solution which involves the ability to identify the flaw and use experience to resolve it!

Defo check pin alignment first and if that doesn’t work then @jofemodo may offer some aftersales support.

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Thanks @riban for the suggesions! The encoder’s JST pins don’t seem to be bent, but I’m including a photo for reference.

I also took a photo of the back of the PCB in case there’s any visible evidence of a dry joint. I have a multimeter but am not sure how I would use it to diagnose this problem.

The switch is between pins 1 & 2 of the connector so, although a bit tricky you could check for open circuit between these pins when the switch is not depressed and closed circuit when the switch is depressed.

A short is possibly more likely than an open circuit with this sort of thing…

I’ve not had a push switch fail and I’ve been pretty cruel to encoders during my Arduino interface days ( It was an interrupt problem but I’d convinced myself it was the encoder and soldered with an oxy-acetylene torch and the welding mask on backwards)

Don’t worry, @plimptm !

A replacement is on the way :wink:


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Thank you @jofemodo for the support! Should I expect just a replacement encoder or the whole controller assembly?

@riban, thanks for the info. I’m interested in trying this as a learning venture. I tested the circuit with my multimeter and couldn’t make it beep with the button pushed. Definitely tricky to keep contact with pins 1+2 while pushing keep the button. Given that pin 2 is the ground, pin 1 is the likely culprit for resoldering, correct?

Indeed, if the rotary encoder is working then it could be that pin has a dry joint or the switch could be damaged.

I used these guys for my Zynthian:

Bourne pec11r-4215k-s002