I was getting occasional power warning lightning flashes on one of my machines- and I tried a handful of known good PI PSU's...and still got intermittent issues on this one machine...no reason as far as I could tell - run the same camera, nothing else that could be sucking more current than the others
I have concluded the USB connector on that board has issues and any sort of movement on the connector gives the lightning flash, kind of backing up my theory
So I just bought a batch of the meanwells as they were inexpensive and means I can wire them into the back of the same IEC mains connector, so halves the number of plugs used per printer
At first I used the GPIO ports on the troubled PI to the meanwell PSU, but had the exact same issues
I was confused - till I broke out the multimeter
The cheap thin jumper wires I used (free with an arduino /breadboard kit - so no doubt cheap/fake dupont connector one end) were not capable enough
(adjusted PSU to 5.2v on its terminals - when verifying the voltage at the board - less than 4v)
so I ended up soldering decent gauge wires to the PI on the back - by the USB port and not had issues since...(about 3-4 weeks so far)
Yes, it will make working on the machine that bit harder now the power is hardwired and the PI is less portable, but fingers crossed made it a lot more reliable
I really don't like the orientation of the power port on the 3 series PI's
It does stick out awkwardly so mounting them neatly is not possible- on the earlier models they were inline with the SD card/network and USB rather than on the side and 90 degrees to where other wires were routed...so (headless) installations were much neater and I don't recall ever having USB port issues on those
Not used the other meanwells on the other 2 printers yet or on any of the other PI's scattered about the place, will do it on an "as needed basis" - or next time I have reason to get into the wiring on them
Regards
Rob