Extruder Temp Reading High / verify_heater Shutdown | VORONDesign | Page 1

odd gull Jun 22, 2024, 2:38 AM

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Hi guys. Hoping someone can help set me straight.

Setup: v2.4 rev A (built in 2019 through 2020) after burner w/ dragon hotend, 2x btt skr 1.4 turbo, linneo harness (self made but 5-600 hours run time.)

I got a verify_heater shut down while warming up the printer for a new print and now the machine will not turn on the hot end heater. I have tried testing the thermistor with a multimeter, no heat and with heat, then verified against a spare. I have continuity all the way to the board.

Now the machine shows the extruder temp being 231.5 degrees.

I'd appreciate any ideas pointing me in the wrong direction and can add any relevant info that may help diagnosis.

Thank you in advance!!

knotty light Jun 22, 2024, 6:24 AM

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what is the config (specifically the temp sensor settings for the extruder)?
what temperature sensor do you have?

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I guess it's showing 231.5°C while at ambient now? If you unplug the thermistor from the mainboard and measure the resistance across it, what do you get?

odd gull Jun 22, 2024, 9:46 PM

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@knotty light

Currently the thermistor that belongs to the machine reads 88.3 ohms and a fresh one from the box reads 87.8 ohms. They are both winsun brand.

The machine reads that temp even if the thermistor is unplugged from the hartk tool head board.

I appreciate your response. Let me know if the two attached machine config screen shots are not what you're looking for and I'll dig up what I can.

Edit: I also just remembered the last few prints the tool head would pause over the center of the bed appropriately an inch up for 30-60 seconds for the last few prints. I had a assumed it was processing a large file? But may that might be related to this issue instead.

knotty light Jun 23, 2024, 4:57 AM

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readings around 88Ω is literally crazy values. Are you sure you're not reading KILOohms? Also, did you disconnect them from wherever they're plugged in before measuring (otherwise, you'll measure the thermistors in parallel with a bunch of other circuitry)?

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88KΩ is more plausible though, that's what a 100K thermistor would read at around 29°C.

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The screenshots you posted are the entirely wrong thing. Not a relevant part of the config, and also a screenshot. Attach the config as a text file, or even an entire klippy.log (since that will include not just the config but also some temperature readings).

odd gull Jun 23, 2024, 5:02 AM

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Dammit. Yes. 88k at 78 degrees in my house.

knotty light Jun 23, 2024, 5:03 AM

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The printer sitting and waiting at the start of a print is usually it waiting for some temperature to be reached. Exactly when it waits for what depends on your startup macro and/or gcode, but if it started doing that for longer than before, it also indicates something is a bit broken.

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At 78 fahrenheats (~25.5°C) a 100K thermistor should be reading about 97kΩ or so, so 88kΩ is still not where it should be.

odd gull Jun 23, 2024, 5:05 AM

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Yea the waiting is new to me.

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I read somewhere the winsun sensors can read low and sometimes adjustments need to be made but I didn't want to change anything drastic without a second opinion.

knotty light Jun 23, 2024, 5:09 AM

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all thermistors have some variance (and they're often not super accurate, which is part of the reason you need to calibrate whatever temperature you print at), but it shouldn't change over time like this.

odd gull Jun 23, 2024, 5:10 AM

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📎 klippy.log

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📎 printer.txt

knotty light Jun 23, 2024, 5:25 AM

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Either your extruder thermistor, the wiring between the thermistor and the mainboard, or the circuitry on the mainboard relating to the extruder thermistor is broken. It's showing a temperature reading of 240°C at ambient (where both bed and chamber read around 26-28°C. 240.5°C for a 100K 3950-style thermistor corresponds to about 385Ω.

odd gull Jun 23, 2024, 5:28 AM

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Right now there is no thermistor even plugged into the machine. The temp didn't change when I unplugged the sensor. I can turn the machine off and back on again and it still reads high. 241 right now.

knotty light Jun 23, 2024, 5:28 AM

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Things you can try:
-Measure the hotend thermistor resistance again. Both at the mainboard (with the connector unplugged), and wherever else you may be able to get to it along the way (if you have some toolhead breakout boards or adapter cables or something). Do this with the heater off and printer cold. It should read somewhere near 100KΩ (assuming it's the 100K NTC thermistor it is configured as)
-You can try swapping over the bed and hotend thermistor connectors at the mainboard, and see if that makes the bed instead show up as bonkers. If the error "moves", it's somewhere in the thermistor and its wiring. If it stays with the thermistor, it might be the mainboad is bad.

odd gull Jun 23, 2024, 5:28 AM

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That makes sense.

knotty light Jun 23, 2024, 5:29 AM

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odd gull Right now there is no thermistor even plugged into the machine. The temp didn't ...

Oh. I was going to sugges you do this. Without a hotend thermistor plugged in, klipper should complain very loudly about the reading being implausible. If it reads such a high temperature with nothing plugged in, something is broken with that input

odd gull Jun 23, 2024, 5:30 AM

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Wonderful. 🤣

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It's getting a little bit late for me to dig in tonight but I'll get into it tomorrow.

Should I see anything visibly wrong on the board around the connection?

knotty light Jun 23, 2024, 5:32 AM

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maybe, but electronics can certainly fail without any visible damage

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does your printer have dual SKR 1.4 boards?

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what I'd try is to move the hotend thermistor somewhere else. Either to the TH1 port (and just remove the chamber thermistor for now), or use one of the seemingly unused thermistor ports on the second MCU (the one called "z")

odd gull Jun 23, 2024, 5:38 AM

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Yes. Dual boards.

When I change the port or board, if it still reads high, then I'm assuming the machine won't do anything except complain or will it "reset" itself once I point it in the right direction?

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I have an octopus v1.1 here from an unfinished v2 350 build. Would it be beneficial to switch it over if the a/b board turns out to be smoked?

knotty light Jun 23, 2024, 5:43 AM

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If you were to move the thermistor over to for example the TH0 port on the "z" SKR board, the printer shouldn't do anything different than now until you change the config (change to sensor_pin = z:P0.24 in the [extruder] section).

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if it turns out the th0 port on one mainboard is toast, what you do with it is entirely up to you. If that's the only thing broken and you have extra thermistor inputs, you could just keep going with the other ones. changing to an octopus means a bit more work reconfiguring and rewiring things, but if the thought of a partially broken controller board worries you, change it over. in either case, first thing would be narrowing it down to actually being the problem.

odd gull Jun 23, 2024, 5:49 AM

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Understood.

No, I don't want to change it if I can just move ports.

I'll dig in in the morning. Thank you for all your help!

odd gull Jun 25, 2024, 2:25 AM

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I moved it over to the same pin on the z board and it reads room temp now.

Perhaps I celebrated too soon. Now it's saying the heater is not heating at the expected rate and I am not able to pid tune.

The only change I made was switching boards to the equivalent plug, and adding z: to the pin call-out in the config.

knotty light Jun 25, 2024, 5:00 AM

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when you start the heater, do you see the temp reading for it go up before it errors out?

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if it's the same hotend, heater and thermistor it should work just like before and not really need a pid tune (the difference between the two analog input ports should be small, a good idea to update but it should work well enough with the old tune).

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i know you can fiddle with verify_heater settings to give it a bit more wiggle room and keep klipper happy, but i've never had to do that for the hotend, and it probably shouldn't be needed.

#Extruder Temp Reading High / verify_heater Shutdown