Not enough power for Pi 4?



  • I had a Pi 4 in my Duet3 setup for the past few weeks but immedicately after running an apt-get upgrade/update cycle the Pi4 will no longer boot from the 5v-->SBC power however boots fine from USB power. It will start then then shuts down ~10s in. I swapped it out for a 3B+ (same SD card) which works fine. I assumed it must be something wrong with the Pi and replaced it with another 4 but it still doesn't boot.

    I'm using an external 3a 5V meanwell PSU going into the 5V in and the PS-On triggers a lower level relay for 24v.

    It had been working with a panelDue previously but still doesn't boot with everything disconnected so drawing too much current shouldn't be it either.

    Any ideas?



  • Measure the supply voltage going to the pi. If it dips (I don't know what the cutoff is), you know the cause. Be sure to measure at the pi side of things to account for wire resistance. You might have had marginal supply voltage and the apt-get cycle made the pi require a tad more power, just enough to get you screwed.



  • Thanks. I'll give it a go when I grab a chance (I installed my 3+ which sits under the Duet in a box so its not the easiest to get to).



  • I'm setting up my new build with a 6HC and a 3HC, running a 4B. I haven't had any problems with the Pi so far, but I'm only doing testing at this stage. I've been moving the gantry around a bit, and I've never seen any blip as far as the Pi goes. Been pretty stable as far as the SBC goes, left it on overnight several times so far.



  • @nriviera said in Not enough power for Pi 4?:

    Thanks. I'll give it a go when I grab a chance (I installed my 3+ which sits under the Duet in a box so its not the easiest to get to).

    Not sure if it is related or not but the pi 4 produces a lot of heat. I have visions of nasty things happening if the pi "sits under the duet in a box". Hopefully you have a fan blowing on it and I am just paranoid.


  • administrators

    If you have other accessories powered from 5V that draw significant current (e.g. a HDMI touch screen) then it is likely that the Duet will not be able to power them as well as a RPi 4, and I recommend you use external 5V power for the Pi.



  • The weird thing was it working fine for weeks with the same setup and stopped as soon as I updated and rebooted. It still doesn't boot with nothing connected to either board.



  • @jens55 the case I have (not my design https://www.thingiverse.com/thing:4025246) does have a fan that vents the whole thing and saves a bunch of space. I thought that may be the case initially but even after removing it and it having plenty of time to cool.


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