#Hotend heats up at power on

1 messages · Page 1 of 1 (latest)

sick girder
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Hello I'm setting up my Vcore 3.1 and when I power on the printer the hotend heats up to 190 degrees. I've been at this for days have tested 2 octopus v1.1 boards with the same results. If anyone could help it would be appreciated.

pseudo temple
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How do you have it wired?

sick girder
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I have it wired the way the diagram shows me

pseudo temple
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Can you post a picture?

sick girder
pseudo temple
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Is it actually at 190⁰ or is the thermistor the wrong type and it's reading a high temperature when it is cold?

sick girder
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Heat is coming off the hotend and the temp stops at 190° and the sensor is correct in the config file

pseudo temple
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upload your printer.cfg please

sick girder
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Here it is

pseudo temple
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why did you redefine the board aliases?

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you have a bunch of stuff you don't need in your user overrides

sick girder
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I did it to test the other hotend ports

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And it was the only way it would let me change the pinout

pseudo temple
sick girder
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Wouldn't that be the heater_pin not the sensor_pin

pseudo temple
sick girder
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I have tried that and have gotten the same results I'm thinking it might be the hotend may be faulty

pseudo temple
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the hotend is just a resister, it only heats up when power is applied. The board has to be supplying it for it to heat up

sick girder
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I just know when I hook up the hotend the heater led comes on if I disconnect the hotend the led shuts off

pseudo temple
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how did you flash the octopus board?

sick girder
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With an SD card

pseudo temple
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and you got the firmware from where?

sick girder
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Ratos

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I followed the setup instructions

pseudo temple
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@summer cedar did BTT swap the chip or something? Only thing I can think of that would cause the pins to be on by default

summer cedar
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I find it extra strange that it maintains 190 degrees.

summer cedar
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Yeah that is really only possible if someone/something set a temperature target.

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@sick girder Can you reproduce the issue, verify that it stays at 190 then download klippy.log and upload it here? Something is fucky!

sick girder
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I stepped out for a bit but I can do that as I get home

summer cedar
sick girder
pseudo temple
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did you modify any files besides printer.cfg?

sick girder
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Not at all just the printer.cfg

pseudo temple
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Where did you get these two octopus boards from?

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and if you set a temp in the web interface for the hotend, does it cause the hotend to cool down?

sick girder
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One was from bigtreetech and the other was from Amazon they have both been tested on other printers and worked fine

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When I set a temp it doesn't cool down

pseudo temple
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idk - maybe @summer cedar can spot something I didn't

summer cedar
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The printer.cfg you've posted here is not the one that's loaded

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Looking at the log !e_heater_pin looks like it's from an earlier boot. The latest one doesn't have it anymore.

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So if it's still doing it, that's not it at least.

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Is there a chance both your heater ports are shorted?

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Can we see your wiring?

pseudo temple
summer cedar
sick girder
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@summer cedar I've always used the printer.cfg file I posted and I've tried 2 Octopus boards with the same results and both boards worked fine when tested on ender 3

summer cedar
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I'm digging through the log again

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Aight @sick girder do you have access to a multimeter?

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I need you to measure the voltage between -/+ on your heater port when the board is powered

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You can use these two screws

sick girder
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I measured it and it's show 23.7v when hotend is hooked up but when I measure it with the hotend disconnected it reads 0

summer cedar
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I would very carefully check the wiring for the hotend.

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If it doesn't measure 24v when it's disconnected, then the heater pin isn't on.

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If you have wago's or some other form of wire joining somewhere along the line, there's a good chance you're running what would normally end up in the - port on the octopus straight into gnd instead.

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Question is what gnd that is, because 2-4A (in the case of Rapido) can kill a lot of electronics.

sick girder
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Only wago's I'm using is from the switch to the power supply

summer cedar
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And you haven't extended any cables by soldering or crimping etc?

sick girder
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No just shortened some of them

summer cedar
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At least we know it's not the board or your config

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If you can, separate the heater cables from the rest of your wiring, run it freely away from the rest, so you can visually see it go from the hotend to the board unobstructed. then see if it's still doing weird shit.

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It's entirely possible that it's shorting to the thermistor wires or something like that.

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Can you send us a pic of the hotend without the silicone cover etc? Maybe there's something interesting going on there.

sick girder
summer cedar
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The octopus has a feature where you can short the thermistor to VIN without causing damage to the board. I don't think you're warned either.

summer cedar
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Can you take one from the front? Need to see the wires

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Can't see the thermistor at all in that pic

sick girder
summer cedar
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yep

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there's your short

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Notice that yellowing/browning

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That part is getting hot AF

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I'm guessing it was squeezed too hard against the metal strain relief

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It's shorting to the thermistor

sick girder
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Yes this was the conclusion I've was thinking it was just needed a second opinion on that

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Thank you for your help

summer cedar
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Looks like a manufacturing error to me

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Pretty dangerous one at that

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Good thing you noticed it

sick girder
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I just emailed them about it wait for a response

summer cedar
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That thermistor short feature on the Octopus is not particularly smart... Sounds like a good idea on paper, but you're really just trading a dead thermistor port for a potential fire.

summer cedar
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correction the protection is on the ADC pin (and will cause a klipper error because of wrong thermistor readout), the gnd pin on the thermistor is just a straight gnd connection. Board didn't actually do anything other than facilitate the potential disaster. To clarify (for your RMA case), what happened here is this: Because of a manufacturing defect, the 24V from the board went through the heater, then on the other side it shorted to thermistor gnd, turning into an always on hotend. All 3d printer control boards control the gnd pin, so when that's sidestepped by a defect like this, you get a constant connection.