Hotend heats up at power on
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.
55 Replies
How do you have it wired?
fair-rose•13mo ago
I have it wired the way the diagram shows me
Can you post a picture?
fair-rose•13mo ago
Is it actually at 190⁰ or is the thermistor the wrong type and it's reading a high temperature when it is cold?
fair-rose•13mo ago
Heat is coming off the hotend and the temp stops at 190° and the sensor is correct in the config file
upload your printer.cfg please
fair-rose•13mo ago
Here it is
fair-rose•13mo ago
why did you redefine the board aliases?
you have a bunch of stuff you don't need in your user overrides
fair-rose•13mo ago
I did it to test the other hotend ports
And it was the only way it would let me change the pinout
no, you just directly use the pin like this:
fair-rose•13mo ago
Wouldn't that be the heater_pin not the sensor_pin
yes, sorry. But you get the idea
fair-rose•13mo ago
I have tried that and have gotten the same results I'm thinking it might be the hotend may be faulty
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
fair-rose•13mo ago
I just know when I hook up the hotend the heater led comes on if I disconnect the hotend the led shuts off
how did you flash the octopus board?
fair-rose•13mo ago
With an SD card
and you got the firmware from where?
fair-rose•13mo ago
Ratos
I followed the setup instructions
@miklschmidt did BTT swap the chip or something? Only thing I can think of that would cause the pins to be on by default
Even if that was the case (it's not, it's a 446) that would only be the case in DFU mode. When klipper is initialized those pins are not on anymore.
I find it extra strange that it maintains 190 degrees.
right?
Yeah that is really only possible if someone/something set a temperature target.
@blazinasian617 Can you reproduce the issue, verify that it stays at 190 then download klippy.log and upload it here? Something is fucky!
fair-rose•13mo ago
I stepped out for a bit but I can do that as I get home
Aight ping me when there's something to look at 👍
fair-rose•13mo ago
@blacksmithforlife 🇺🇸 now it just continues to heat past 190 degrees
https://github.com/Rat-OS/RatOS-configuration/blob/v2.x/hotends/rapido.cfg#L15
yet your log shows
did you modify any files besides printer.cfg?
fair-rose•13mo ago
Not at all just the printer.cfg
Where did you get these two octopus boards from?
and if you set a temp in the web interface for the hotend, does it cause the hotend to cool down?
fair-rose•13mo ago
One was from bigtreetech and the other was from Amazon they have both been tested on other printers and worked fine
When I set a temp it doesn't cool down
idk - maybe @miklschmidt can spot something I didn't
Well !e_heater_pin explains it
The printer.cfg you've posted here is not the one that's loaded
Looking at the log !e_heater_pin looks like it's from an earlier boot. The latest one doesn't have it anymore.
So if it's still doing it, that's not it at least.
Is there a chance both your heater ports are shorted?
Can we see your wiring?
near the top of this thread
Yeah was looking at it, can't immediately see anything wrong. The USB power jumper is in, but that won't cause this.
fair-rose•13mo ago
@miklschmidt 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
It's very odd to say the least
I'm digging through the log again
Aight @blazinasian617 do you have access to a multimeter?
I need you to measure the voltage between -/+ on your heater port when the board is powered
You can use these two screws
fair-rose•13mo ago
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
That points to a short somewhere. Somehow your hotend is shorting to gnd
I would very carefully check the wiring for the hotend.
If it doesn't measure 24v when it's disconnected, then the heater pin isn't on.
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.
Question is what gnd that is, because 2-4A (in the case of Rapido) can kill a lot of electronics.
fair-rose•13mo ago
Only wago's I'm using is from the switch to the power supply
And you haven't extended any cables by soldering or crimping etc?
fair-rose•13mo ago
No just shortened some of them
Then check the hotend heater cable for damage
At least we know it's not the board or your config
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.
It's entirely possible that it's shorting to the thermistor wires or something like that.
Can you send us a pic of the hotend without the silicone cover etc? Maybe there's something interesting going on there.
fair-rose•13mo ago
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.
Can you take one from the front? Need to see the wires
Can't see the thermistor at all in that pic
fair-rose•13mo ago
yep
there's your short
Notice that yellowing/browning
That part is getting hot AF
I'm guessing it was squeezed too hard against the metal strain relief
It's shorting to the thermistor
fair-rose•13mo ago
Yes this was the conclusion I've was thinking it was just needed a second opinion on that
Thank you for your help
YW, hopefully you can get that one RMA'ed
Looks like a manufacturing error to me
Pretty dangerous one at that
Good thing you noticed it
fair-rose•13mo ago
I just emailed them about it wait for a response
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.
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.
I've talked to BTT and they'll see if they can incorporate a fuse into the thermistor gnd connection or something similar on future boards.