Recently I have experienced an issue that I want to share in case it helps someone.
After buying the Zynthian KIT V5, assembling and testing flawlessly; –in the same day–, died my Zynthian V4 DIY project. A coincidence? Initially I thought that.
The Raspberry PI400 used in my DIY project stopped working suddenly. No lights. No activity. All disappeared. Yesterday, after buying a new PI400 to replace it, I rescued it to life again.
A moment ago I went to check its sound to my studio, but for my comfort as on the previous occasion, I did not put the PSU of the PI400. Instead, I used the already connected PSU of my Zynthian V5, thinking that was the same 5 volts…
Oh my God! I discovered in a second instance that was quite different. After beeing shocked for a second time NOT WORKING Raspi ,I realized that the voltage on KIT Zynthian V5 was 24 volts instead of 5 volts of Raspberry PSU.
So, as you are guessing, my new Raspi 400 is a corpse now… Man is the only animal that trips twice on the same stone. But the clue is that I never imagined that working with a Raspi the voltage could be different to 5 volts.
For sure it does. We decided to use a higher voltage to increase the available power without worrying about high current. For getting 30 watt at 5V we would need 6 Amp. Managing big currents is normally more challenging that managing big voltages.
Indeed, the V5 can be powered with voltages from 9 to 48 V. The bigger the voltage, the lower the current. The official PSU is in the middle of the range: 24 Volts.
@erasmo, i’m really sorry to hear so killed your Pi400. I would ask our provider to use bigger characters to label the PSU voltage
My confusion came from the fact is that I was aware that Raspi 5 used the same 5 volts than Raspi 4.
But once said that, one thing is Raspi and other very different is Zynthian V5, which works at a proper voltage of 24 for several good reasons explained properly in this forum.
So my advice was addressed to avoid someone the same mistake.
Sorry for your loss, it’s always really annoying when one fries a piece of equipment beyond repair.
But I’m at a loss to understand how the PSUs can be mixed up - The 5V supply to a PI400 or Zynthian V4 is via an USB C connector, whereas the supply for the Zynthian 5V is via the more classic round connector, so it’s not possible to plug one into the other.
When I made my ZYNTHIAN DIY V4, I cut the Raspberry PSU cable to insert an interruptor, to handle ON/OFF in a more convenient way, and put a cylinder socket type female on case and the proper male one on cable.
Unfortunately the same type and size found on ZYNTHIAN V5.
So when I tested my V4 with cable of V5, the only thing I had in my brain was that both Raspis voltage was = 5V.
The PSU may be a different voltage and a different polarity. Always check both!
An additional tip: do not add a switch inline with the RPi power inlet. These are prone to increasing the resistance and hence reducing the current flow. Inline switches have been a common cause of issue with zynthian.
I can second that, I have a Zynthian at work, which was powered by a left over power supply with inline switch, and I frequently had undervoltage issues, until I removed the switch. It didn’t happen all the time either, so it wasn’t obvious what the problem was.
At home I have one of those mains switches built into a combined plug and socket so I can switch power to my Zynthian on the mains side.
When I bought the first P5, I accidentally powered it up to 12V. It stopped working, but after about an hour it started again. It probably has a self-resetting fuse. Have you tried turning the Raspberry Pi back on?
Yes, I discovered that searching on internet. After throwing away my 2 damaged Raspis, I recovered them and put on my desktop …waiting for a miracle that could bypass 24 volts all of a sudden!
Hi, Maybe the Raspberry Pi’s input protection diode is faulty. This can be seen on the electronic plans of the Raspberry Pi boards, for example for a Raspberry Pi 4, it’s this circuit: SMBJ5.0A-TR
It was not necessary to change the diode. A simple test without the diode would have allowed us to see if the rpi was dead. This diode has no effect if the rpi’s power supply is correct, it is just a protection. On the other hand, if the power supply has too high a voltage (inadequate power supply, >6v), the diode shorts out. The diode reacts in the same way when the polarities of the rpi’s input are reversed. In general, after using an unsuitable input voltage, the diode remains permanently shorted. In this case, the rpi no longer receives power and therefore the rest of the electronics is not damaged. This is why it is advisable to replace this diode. It is easy to see if the diode is dead, because it becomes very hot when the rpi is powered on. This is one of the solutions used to protect electronic devices. I am sorry that your rpi is permanently dead.
that could bypass 24 volts all of a sudden!