Zynthian v5.1 kit won't boot

Hardware
1

My Zynthian v5.1 kit will not boot. Completely dead. Any suggestions?

2

Hi @tkc - sorry to hear you’re having boot issue. Have you see the “first boot” section of the wiki?

Is this a first boot?

3

Thanks @tunagenes for responding. This is not a first boot. I have used this Zynthian extensively for many gigs and rehearsals. This is the first time it completely went kaput.

I have another gig Friday. Fortunately I have a backup Zynthian on a Rbpi 4, so I’m not completely screwed, but it also appears that RTP-MIDI support has been deprecated so I can’t use my iPad to change songs over WiFi (I was using the onboard MIDI 5-pins to connect to my iPad directly for this).

Does anyone have any quick suggestions to bring this unit back to life?

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4

Here’s some ideas-suggestions: Carefully observe the screen when you turn the power on - you should see a flash after a second or three. If not I’d suspect the power supply connection at both ends - is it plugged into good AC, and is the barrel connector solidly in?

If you are seeing that flash, but nothing after that you could open the Z up so you can observe the Pi’s status lights, or try a freshly written or backup SD card, first in the Z’s socket, and if that doesn’t work in the Pi’s socket. Do you have multi-meter you could use to do some basic power troubleshooting? You could also see if it’s actually booting (maybe just a screen prob) by seeing if you can get to webconf.

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Thanks for the suggestions @tunagenes . The screen does not flash and the keyboard connected to the USB doesn’t power either. I strongly suspect it is a power supply failure.

6

Do you have a meter so you could test it?

The power supply can be “Flexible power supply with input voltage from 9 to 48V.” - from the specs so you could probably get one pretty quickly.

Here’s a recent post with some info on the barrel connector needed.

I don’t know what country you’re in and whether you can wait for the Zynthian shop to send one, assuming it is bad.

7

Thanks @tunagenes I think I used the wrong term. I meant I think the issue is with the switch itself or perhaps with how power is conveyed to the rest of the unit, not with the power adapter cable. I suppose I’ll need to invest in a multi meter to troubleshoot further. I’m in the USA (Portland, Oregon to be exact). Hopeful that there is some guidance somewhere on how to replace a faulty switch if indeed that is what has failed!

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Hi @tkc!

It’s the first time i hear about a faulty power switch. Of course, it’s not impossible, but we use high quality parts, with long life cycles.

imagen
imagen611Ă—368 49 KB

(this is, at least, 2 power cycles / day for 8 years, minimum)

Why do you think the switch is broken? Have you perceived a “change” in the “action feeling”?
Or could be the power connector that is broken? Perhaps a sudden jerk on the cable?
Are you sure it’s not the SD-card that got corrupted, for instance, by losing power while recording to the SD-card?

Did you test the power supply to check it’s OK? Have you tried to power the V5 with an alternate power supply? Any power supply with this parameters would work:

  • Voltage: From 12 to 48V
  • Power: >= 15W (probably you can boot and test the system with less)

All the best,

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Thanks @jofemodo for getting back to me. Of course I’m not certain of anything at this point, only that it does not boot at all. Here is everything I can provide on this:

  1. For the last several days before this happened, I would turn on the Zynthian and noticed that it made an audible “click” a few seconds after it powered on. Since it booted up fine I thought nothing more of it.
  2. I have a MIDI keyboard that gets its power from the Zynthian’s USB. Ever since this started happening, when I turn on the Zynthian, the keyboard will briefly light up for less than a second and then powers off.
  3. I have a full backup SD card that is a near replica of the one that I use on stage. Neither card boots.

I imagine that if it was the power supply, we wouldn’t be seeing the MIDI keyboard turn on at all. That’s why I think whatever it is, it is within the Zynthian box itself.

I have not yet tried booting up the RBPI 5 from a separate power source. I saw on a post earlier that the Zynthian box “steps down” the power before it goes to the RBPI so I wanted to confirm the specs of the RBPI power supply first. In all honesty, though, I don’t know what that would get me if I were to boot the PI by itself, except knowledge that it is something in the Zynthian chassis.

Please let me know if any of this context helps in pinpointing where I should look next. Thanks again for your help!

Regards,
TK

10

You can test powering the RBPi directly with a USB-C power supply. This will power all the rest.
Off course, don’t connect the 24V power supply in this case.

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Some noted in the Data Sheet fragment i copy/pasted above it’s specified:

Contact Rating: 5A /15VDC

But if you read below, you can read the Dielectric Strength is 1500V RMS.
And they also talk of an “Insulation Resistance” of 1000MOhm at 500VDC.

Well, this “Contact Rating” is regarding cutting-power. Aka, the capability of cutting a current without generating an electric arc.
So the specification is saying that with a voltage of 15V, the switch can cut a current of 5 A safely. At a lower voltage, you could cut more current, and less current at higher voltage. But electric arc physics are not linear. The manufacturer should give a curve with the cutting current for each voltage, but instead they simply give the value at a “medium” voltage. Not ideal, but enough if you are far enough from the danger.
For a high power / high-performance switch, for sure the datasheet would contain the curve, but it’s a low voltage switch for domestic appliances, so we only have a single point value.

Regarding zynthian V5, the official power supply is 24V / 2A, so i think we are far enough from a dangerous current that could “melt” the contacts.

Thanks a lot for being open eyes!! It’s a pleasure to work with zynthian community! Really!

The best,

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Thanks @jofemodo . The unit boots up no problem when I plug a 5v power supply directly into the Zynthian. I’m pleasantly surprised this even includes the onboard monitor!

Does this narrow down the issues? At least it seems good news that the Zynthian itself is intact and that we just have an issue providing power. I still doubt it is the 24V power supply, because why then would it briefly power the MIDI keyboard and then drop power? However, I’m willing to try a different power supply if you still think this is more likely.

Are there targeted tests you would recommend performing using a multimeter (which, full disclosure, I have never owned or used)?

Thanks!

TK

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If everything is working when powering the RBPi, then i think we have the 2 finalists for the award:

  • the power supply is broken

    • it could be cord or connector
    • it could be the power supply itself

  • something in the mainboard’s power circuit is broken

    • it could be electronics
    • It could be mechanical (the switch / connector)

Replacing the power supply is not expensive, so this would be the “desired” case. You should check this first.

Replacing the main board is expensive, but not excessive. Shipping to USA is what push up the total cost. In the other hand, fixing the main board’s power circuit is not difficult if you find the right person with the right tools. I could help to determine the failing part.

The best,

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IMG_2669
IMG_26691920Ă—2560 1.12 MB

I found this universal power adapter. If I set this to 5V, will this be safe to test powering up the Zynthian from the power input?

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No. You need at least 12V. 9V could be enough, but not less.

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Thanks @jofemodo . I set the power supply to 12V, plugged it in, and turned it on. Same result as before. No power.

I then opened the case and plugged the RBPi USB-C power into the RBPi USB-C slot. It booted up flawlessly.

I am now wondering if this may be the culprit:

IMG_2672
IMG_26721920Ă—2560 716 KB

The curve where the cable connects to the board appears to match an issue that was called out in the “First boot” section that @tunagenes originally pointed out to me:

Might this need replacing or repairing? Will I likely need a new cable?

Or, is it possible still that a 24V power adapter is the only issue?

Thanks, TK

17

Sorry, one last question @jofemodo . Since the RBPi will boot up using the standard USB-C power, is it safe to use the Zynthian this way for my gig tomorrow? Or did you suggest this merely as a troubleshooting step, that otherwise I should not try and do a high-stakes performance with power going directly into the RBPi?

thanks,

TK

18

Powering the RBPi directly is OK. You can do It safely for your gig, if the power supply is good enough.

Regards

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Thanks @jofemodo , that’s a huge relief! I have rehearsal tonight so I’ll be able to give it a good run before tomorrow’s show.

Please let me know your thoughts on whether there’s still value in trying to test a new 24V power supply or if you think this for certain is an internal board issue.

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If you are confident with the power supply you already tested, i would think there is something broken in in the mainboard’s power circuit.

You should think on fixing or replacing.

Regards