VIN under-voltage event (*variable value* V)

A Former User

@nicholasport Here is the only image (very poor quality) of the errors the one time I was able to see.

jay_s_uk

@nicholasport what board are you using? What firmware?

mrehorstdmd

@nicholasport Is the controller power supply also trying to power a bed heater?

Phaedrux

Have you checked the voltage output of the PSU with a multimeter when you get these errors?

dc42

@nicholasport said in VIN under-voltage event (*variable value* V):

Hi, unfortunately I cant run this command directly after the errors. Only once has the printer reconnected after shutting down. Every other time the printer shuts off and the screenshot below is what pops up. I then have to turn of the power supply and turn it back on to get the duet to reconnect to the web client.

It sounds to me that the PSU can't handle the power requirement and is shutting down.

A Former User

@jay_s_uk I am using the Duet WiFi 1 and running firmware version 2.01 which I know is really old.

A Former User

@mrehorstdmd The bed heater and tool are wired separately to the psu if that's what you are asking.

A Former User

@dc42 The PSU I have is a evga supernova 750 g2. A 750 watt psu, I had plans to make this dual extrusion from the start.

dc42

@nicholasport said in VIN under-voltage event (*variable value* V):

evga supernova 750 g2

Here are some possible causes of the power brownouts:

That's an ATX PSU. Most ATX PSUs need minimum loads on their +5V and +3.3V outputs. Otherwise, with only the 12V output loaded, the voltage on the 5V and/or 3.3V rail rises too high, causing the PSU to cut out.
Check that then VIN terminal block screws are still tight. It's common for them to lose grip after a few hours or days due to thermal creep, especially if you used stranded core wire without ferrules securely crimped on.

mrehorstdmd

This post is deleted!

A Former User

I've determined it is the bed. I've been busy with work, but this morning I tried several prints with just the head, and no bed heating, and it worked perfectly fine. Then I tried again with bed, and I can't even heat up the bed and start the print, it crashes before the bed even hits 30 degrees

Phaedrux

Yes it would seem that the bed is drawing too much power and the PSU can't keep up.

A Former User

Just as clarification, there is almost no way the PSU is the problem, I haven't changed the head, or bed in over two years and the printer hasn't started having this problem until the past month. So unless I'm missing something, it simply would not make sense that the PSU can't handle the same duties that its worked with for the past 5 years. I checked all the wiring to the board and even removed the bed and checked the resistor and thermistor in the bed. I'm on 1.x firmware right now, so I have been reading through the documentation on upgrading to the 3.0 then 3.x firmware. attached is the original config.g and the one I've created for 3.0 firmware. I noticed that maximum instantaneous speed changes for my old config are way higher than what was said to be the maximum. Is this a problem, or is this going to possibly improve my printers and make them less jittery?config(new).g config(old).txt

Phaedrux

Can you measure the resistance of the bed heater? Perhaps the heater itself has developed a short or deteriorated. The same could be said for the power supply. Things work until they don't. Past performance isn't indicative of future performance. You ran without the bed and it worked without issue, so somewhere in the chain of the bed there's a fault.

As for updating to RRF3 which 1.x firmware exactly are you on? If you can manually update to 2.0 you can more easily update to RRF3.

Here's a post that details the process: https://forum.duet3d.com/topic/18962/firmware-not-updating/4?_=1623782288258

Phaedrux

@nicholasport said in VIN under-voltage event (*variable value* V):

I noticed that maximum instantaneous speed changes for my old config are way higher than what was said to be the maximum. Is this a problem, or is this going to possibly improve my printers and make them less jittery?

M566 X72000 Y72000 Z72000 E1200:1200 ; Set maximum instantaneous speed changes (mm/min)

That is a very very high jerk value. Your accelerations and print speeds are conservative enough that that high number rarely would have come into play. Your delta would be making sharp corners, that's for sure though.