Just as a note to back up previous messages. When I first started I had the same problem and my power supply usb cord was a short 10mm (not cm) and I got the warning. Based on what I read as above, sourced some larger diameter wired cord/plug and the problem went away. I read the specs on the cords from various sources and bought the ones with the biggest power supply wiring that I could find.
Problem solved.
Regards
You get the message when there is s sudden drop below about 4.6V, you can look up the specifics. It only has to be a very brief drop, something you can't measure unless you Oscilloscope is pretty good, mine can only just see it.
It is often a sudden current draw that the PSU responds to and the voltage drops as it tries to compensate.
Many desktop power supplies cannot react fast enough, I know my 100W one cannot.
Also for standard plug in types, many of these drop the voltage as the current increases, again some cannot respond fast enough.
That's after you have you voltage adjusted to compensate for cable and connector loss as it gets to the Pi, hence decent wires.
Things like sudden motors turning on (fans) can cause this.
Harddrive/SSD of course especially Nvme as they are power hungry compared to the old Sata drives, that's more the PSU dropping the voltage as the current nears increases.
If it only happens at boot time and the Pi works, it probably easy to ignore it, just don't keep booting up.
If it happens while using it, then you have a bigger problem.
seems there is some serious issue with my board.
i dont see any voltage that is going below 4.7 entire my power cycles, monitored using oscilloscope. plugged my oscilloscope to both 5V rail and RST pin of the 3pin low voltage trigger IC.
even after multiple restarts and power cycles i dont see neither RST trigger nor voltage going below 4.7V across 3 pin IC.
and just for my trail i ve turned off the power supply and from below we can see clearly RST has triggerred by 3 pin IC when voltage goes below 4.6V as intended.
so, it is clear that my supply side there is no issue. but still in Octopi UI i see undervoltage warning. "Under voltage detected from begining of BOOT err 0x50005"
so, i've traced until where the signal goes. and i found the IC below which receives the signal.
R8 value is as intended - 470Ohms
continuity between470ohms and 3pin IC all good.
not sure what IC Is doing with the signal and reporting to the operating system. any suggestions and any datasheet available withanyone?
i tried googling i dont find any data sheet or anything about the IC.
is my board gone?
i wonder why does the error come even after disabling in CONFIG file?
I had a similar issue powering from gpio.. bought a usb-c connector and still had the same problem until I used the thickest wires that would fit and the message finally went away.