Abnormal temperature head detected
Welcome to the Community! 😀
Sorry, but I don’t fully understand the audio you attached. Would you mind writing a reply with more information about the issue you are experiencing? Also, would you tell me the brand and model of your Printer and type of filament you are trying to print? Also, what Slicer are you using? Would you send me some screenshots of the Slicer settings?
With that information I will be able to get a diagnosis of what is happening and build a solution.
I am looking forward to your response.
Hi Pablo, I’m using the LK4 printer with PLA filament and the Slicer software came with the printer on a SD card. “Abnormal temperature head detected “ is showing in the menu interface halfway through the print. I Y-tube the problem and did what was shown to do and the problem still shows the error.
Thank you for your reply! Now I got it more clear.
First, I have a couple of questions for you. Have you been printing with this printer or is this the first time you use it? Did you get to see if the temperature shown on the display was different to the one set up (210°C)?
Would you describe what you have done so far? In order to check if there is something that needs to be adjusted. For instance, did you follow the procedure shown in the following You Tube video: https://www.youtube.com/watch?v=euWM5J0BwhI ? Unfortunately, this video doesn't show much. Although it is made by the printer manufacturer. The information provided is not clear. If the message says “Abnormal head temperature is detected”, the problem might be related to the mainboard (according to the manufacturer). But, if the warning message is “Abnormal bed temperature is detected”, the problem might be related to the hot end thermistor (also according to the manufacturer). Here is when I get confused by the information provided by Longer 3D: why is there a problem with a warning mentioning the bed while the cause might be in the hot end? Strange, isn’t?
Before going further, I suggest you check the wiring of your thermistor. This small temperature sensor is located on the heater block, right next to the heater. Verify if there is a wire loose on the Hot End and then check the connector on the mainboard. Remember to unplug your printer from the power cord in order to prevent electrical hazards. Remove the mainboard metallic cover and make sure it is properly connected and it isn’t loose. Some printers add some glue on the connectors to ensure they don’t get loose. In the following picture you will see the position of the thermistor in the hot end.
I have been doing some research related to the LK4 Pro printer and the warning is related to thermal protection, which avoids further damages or serious incidents (like fire hazard). Normally, this safety protection is called Thermal Run Away. Basically, this protection aborts a print when there’s something wrong about the thermistor readings and the indicated output temperature, looking at the rate of rise of temperature according to a lapse of time. For instance, if there is a 2°C increase requirement and this temperature doesn’t rise in a certain amount of time (10-15 seconds), the warning will come up on your display while stopping the printing.
Also, you could check the thermistor. For this procedure, you will require a multimeter (selected in the kOhm range). First, unplug the connector from the board and place both pins of the multimeter on the thermistor connector and check the value measured. Since this sensors varies the resistance in accordance with the temperature, there is a chart with different resistance values for each temperature: https://www.bapihvac.com/wp-content/uploads/2010/11/Thermistor_100K.pdf . In this case, when measuring at ambient temperature (25°C) the value should be 100.000 Ohm (or 100 kOhm). If you grab the thermistor with your hand the resistance value should be different. If your body temperature is at 36°C, the new reading should be around 60 kOhm. Let me know what is the value you get to read.
Looking at your picture, I can notice that this issue happens in the middle of the printing. Does it happen like this all the time or sometimes does it at the beginning of the print? Therefore, there could be some PID auto tuning issue also. But, I will wait for your response in order to reach some conclusions.
I am looking forward to your reply.
First let’s address those questions:
1.) Have you been printing with this printer or is this the first time you use it?
YES, It’s the first time I’ve used this printer is brand new.
2.) Did you get to see if the temperature shown on the display was different to the one set up (210°C)?
No I didn’t check to see if the temperature on the main interface was different than the previous reading. Actually, I retried to start over several times and the same results came about.
3.)Would you describe what you have done so far? For instance, did you follow the procedure shown in the following You Tube video.
Yes, I did exactly what was shown to me via the Y Tube video. And check the wiring of my thermistor located on the heater block, then check the connector on the mainboard.
4.) No I did not check the thermistor. I do not have a multimeter, did my come with this Longer LK4 printer. So I couldn’t check the value measured.
5.) Does it happen like this all the time or sometimes does it at the beginning of the print?
All the time with error showing on the main interface. I’ve tried other G-code like the birds and the whistle. At the beginning while heating up bed plate and heat block before the print will start a short time later the error is displayed on the main interface.
I’ve only made half a print with the previous picture I sent you….bottom of the birds half way through.
I will order me a thermistor to check the value of Ohms.
Thank you for your answers!
Regarding answer 5), from what I understand, the print stops a few minutes after the bed and nozzle reached the temperature target, is that correct? If this is the case, would you send any file to print and check if any of the temperatures varies when the target value is reached? When you start a new print, both temperatures (bed and nozzle) should stay stable in the set up value, which in your case is 60°C for the bed and 210°C for the nozzle. Please, let me know if this values doesn’t change when reached
I will order me a thermistor to check the value of Ohms.
I think you wanted to say that you will order a Multimeter to check the thermistor resistance, right?...
I look forward to your response for the thermistor resistance value. If you don’t have a multimeter, maybe a friend or a neighbour can assist you with this instrument. Remember to disconnect the thermistor from the board when checking the measurement.
I read that some users had to loosen up the screw that holds the thermistor to the heater block, because it was too tight from the factory (affecting the wires). If the metallic screw that holds the thermistor in position is too tight, it could damage the wires. This will make the bare wire touch the heat block which is metallic to, affecting the reading (because the resistance changes). Would you send attached a picture of the position of the thermistor? If possible, make it as close as you can.
Also, would you send me the exact name and version of the slicer? Because in the Longer web page I have the option to download two types of slicers: Longer Slicer or a type of Cura version. Normally, in the Help tab you will find the option of the software. A screenshot will be very useful. I will need this info to explain to you how to connect the printer and your computer in order to make some adjustments. Another information that will be very handy is the firmware version. You can find this data scrolling in the user interface panel.
Just to make sure, your printer is a LK4 or a LK4 Pro? Because there is a slight difference between both printer models. Especially when it comes to the user interface model and firmware (which is the language that controls the printer linking the software with the hardware).
I look forward to your response.
If the metallic screw that holds the thermistor in position is too tight, it could damage the wires. This will make the bare wire touch the heat block which is metallic to, affecting the reading (because the resistance changes). Would you send attached a picture of the position of the thermistor? If possible, make it as close as you can. I remove the shell protector case to find the “Heater wire “ next to the thermistor wire was touching the “
Heater block” causing the abnormal temperature head detected on the main interface.
I think you wanted to say that you will order a Multimeter to check the thermistor resistance, right?. Right! And I will but me Multimeter.
What to do if the Heater is Not in the proper hole conducting the heat? The White wire was not in the hole as shown in the screen shot: is that the “Heater” pointed out in the picture you sent me?
Thanks, I wait for your response to adjust this problem.
Also, I will Y-Tube the problem to get some ideas on what can of materials to fixed this problem. Glue or reconnecting the Heater wire to the Heater block properly.
You suggest that I check the wiring on my thermistor. This small temperature sensor is located on the heater block, right next to the heater. Verify if there is a wire loose on the Hot End and then check the connector on the mainboard. Well that is the problem with the temperature sensor as shown in the picture and Not the Heater. The temperature sensor was not connected. Dangling loosely when I remove the metallic case as you suggested. Thanks! Now What? This by not be expensive…😀😀. I look forward to your response to save this printer of mine. Thanks ounce again.
Sincerely Thurman Steward
Thanks for getting back in touch with me. I Y-Tube the problem and Notice there was no screw for the temperature sensor to hold in place and it seem the screws that the thermistor held in place are tight to. Maybe I should loosen up those screws that is to tight because it look like the wires are touching the heater block. The printer is a Longer LK4 not the pro.The temperature seem to be as you stated about the bed being 60 degrees and the nozzle at 210 degrees. Here’s that screenshot and short video of the temperature shown in the main interface.
Thank you for the valuable info! Let's go step by step… 😎
I apologize I didn't answer before. But thanks to the information you provided, there are a few things to consider.
First of all, I find it hard to believe that the thermistor wasn’t attached to the heater block. If I were you, I would write to customer service of the company who sold you the printer, for the inconvenience. Anyways, let's work to solve it. Attaching the thermistor (placed at the end of the wire; yes, that little tip… 😶 ) is not complex; all you need is a M3 screw and a screwdriver. This screw is placed on the small hole you can see in the picture you sent me.
In order to avoid any damage, do not apply too much force or you might end up breaking the thermistor or the wire. The force applied should be enough that the thermistor touches the heater block. The best way to place the thermistor is to pass the screw between the both wires and screw it to the heater block. I am attaching the following picture for reference.
The previous assembly is from an Ender 3 Pro, But applies to your LK4 hot end, since both are based on the same design. As far I can see, the heater is placed correctly. But, check if the small screw that holds it in place is tight. Otherwise, the heater will start to move once the printer starts to print. For this screw you will need one of the small Allen wrenches (the manual says that all Allen wrenches are provided).
Once you manage the placement of the thermistor, try to print a small model for testing. Be aware of checking the display in case you notice any temperature variation. If the hot end temperature is stable, then the problem is solved. If the result is successful, you won’t need to use the multimeter this time; but I promise you will use it sometime in the future… 👍
Nevertheless, I was able to tell there is a problem with the bed temperature measurement as well (based on the video you sent). Since the target value is 60°C, it seems the bed’s thermistor is not working properly or the bed heater is not receiving the proper power. Just to be aware, what is the voltage value you have in your house from the electrical company? Is it 110V or 220V? Related to this, in what position is the voltage supply switch from the printer’s power supply? If you take a look at the power unit (located under the bed), you will see a red switch, which allows you to set the correct voltage input according to the voltage you receive in your house. If it is 220V, place the switch where you can see the 220V legend. On the contrary, change it to 110V. In the following picture you will see a reference for the previous description.
When looking at the screen (interface), you will see both temperatures: bed and nozzle (the format is xx/xx). The value on the right indicates the target temperature, the one you set up in the slicer (60°C for the bed and 210°C for the nozzle). The value on the left is the actual value measured by the thermistor in each component (one thermistor for the bed and another for the nozzle). In your case, both target temperatures are not being reached. Especially the bed temperature, which is 31°C according to the video. The temperature on the nozzle is closer to the target value (117°C); but is not correct. In all cases, both temperatures should be the same as the target temperature. Otherwise, there is a problem.
In conclusion, if the supply voltage switch from the power supply unit is correct. I will recommend you to check some parameters and perform some tests. But first, I would like to write some words about the thermistor screw; because I might have misunderstood you. When I refer to a sensor I mean the thermistor. Because the thermistor is a temperature sensor based on a variation of the resistance. Therefore, from now on I will only write thermistor in order to avoid further confusion… 😀
The heater block is the little aluminium cube which has the thermistor and the heater, only has space for one screw for the thermistor and one for the heater. The heater is located inside the heater block and the thermistor to a side. Both are held in place by only one screw. In the following picture I am showing all the components I wrote about.
Therefore, that is why I misunderstood you, because you mentioned screws in plural. The idea of loosening the thermistor screw a little bit is to verify that the cable or the thermistor itself are not damaged (like I wrote a couple of paragraphs before). Also, the resistance value of the thermistor at room temperature (measured with the multimeter) is very helpful in order to verify if the thermistor is damaged or not.
However, the video you sent adds more to my suspicions about a major issue. Because the bed is not reaching the target temperature of 60°C. So, I appreciate that info!
One last thing for now, does the heat block comes with a silicone cover (like the black one on the last picture)? Because that cover prevents temperature variations of the heat block. I am asking because I didn't see it in the picture you sent.
In conclusion, in order to keep things under control, make sure to follow the indications I wrote in this reply. Then, we will work from here…
I am looking forward to your response.
Hi Pablo, I reinserted the thermistor but without the M3 screw and I did switch the wires in the motherboard and assemble everything back together. I tried to run a print and the
main interface is showing:
”Abnormal Bed temperature detected”…now what?
And the bed itself has begun to peel away around the corners ounce the bed reaches a certain temperature. I’m reading your suggestions and making those changes and identifying those important areas where needs to troubleshooting. But this is a brand new printer that came like this. Minimum assembly but easy, which made me think I was off with a good print. Problems in the beginning is making me think I bought the wrong printer. But me and the printer will be resilient in getting this machine functioning properly. I’m going to buy those necessities for this longer printer and try this again.
Everything is put back together and still this abnormal bed temperature detected is showing on the main interface.
Thank you for getting back!
Great! You made improvements by putting components where they must be. Bearing this in mind, I will recommend some basic verifications just to make sure everything is in place.
In the last picture you sent, were you able to see in the main interface if the measured temperature was the same as the target temperature? In your previous reply, the temperature of the bed was at 31°C, while the target temperature was 60°C. Please, would you check what are the temperature values (both bed and nozzle) when the warning signal appears? Unfortunately, the YT video is not clear about the issue related to the abnormal temperature issue. In addition, did you verify if the thermistor of the bed was in place? Because if the hot end thermistor wasn’t in place, the same could happen with the one that measures the bed temperature. This thermistor is placed under the bed surface and should be attached in the middle and covered to the bed.
But this is a brand new printer that came like this. Minimum assembly but easy, which made me think I was off with a good print. Problems in the beginning is making me think I bought the wrong printer. But me and the printer will be resilient in getting this machine functioning properly.
Many printers are pre assembled in the factory, so the final user is only a few steps away from having the print running. Despite this, it is always recommended to verify connections, bolts, belt tension, etc. In addition, I suggest performing some calibrations in order to have good printing results. Even if the manufacturer says that it is calibrated in the factory (I prefer to control it myself… 😀 ).
I would like to see what happens with the bed peeling. Would you send me a picture of that? Also, at what temperature does it happen? Since you are printing with PLA, the bed temperature shouldn’t be higher than 55°C. Since it isn’t a high temperature, I wonder what is causing the bed to peel off. Also, check if the power cables of the bed are correctly attached to the bed.
Related to the bed surface, does it have a magnetic flexible build surface? Can you remove it from the bed or is it stuck to the bed? If you have the second option, maybe the glue is affected by the temperature or maybe there wasn't enough glue placed. If this is the case, you could use some black metal paper clips, like the one shown in the following picture.
Place four clips, one in each corner and make sure the arm of the clip is placed towards the bed movement. Otherwise, they will touch the vertical frame when the machine starts printing, due to the bed displacement.
Based on this experience, I would recommend you to verify all the wiring connections. Make sure that all components are well connected and there are no wires damaged. Remember to unplug the printer in order to avoid electrical hazards. Also, control all the bolts and belt tension. Did you check the power unit switch and compare it with the voltage value of your electrical network? Please, send me pictures of whatever you find is out of place or you have doubts.
Since the issue is related to bed (or at least is what the warning is about… 🤔 ), take a special look at the connector of the heated bed. Many printers have a support that holds the wire with a support, which avoids undesirable efforts while the bed is moving when printing.
One last thing, since the printer is new, did you verify with your vendor if the printer is still under warranty? Because you can contact him/her and ask for a refund for the problem you are having. For example, you can mention that the thermistor of the hot end was detached and the bed is peeling off.
I am looking forward to your response.
@placherre: Hi Pablo,
Does the heat block comes with a silicone cover ? No...not like the picture you showed me. I took everything apart with the Heat sink, Heat block, Nozzle, Thermistor, Heater cartridge, Bowden Couple and notice that the M3 screw is Not a hole for the M3 screw just glue stain. So, I glued the thermistor back into the hole that touches the heater block. It worked, because none of the M3 screws I bought fit into that hole. Then the Nozzle was clogged with filament and the Heat sink to, I cleaned both parts with the tools. Then I notice that the filament was stuck in the white tube and was hard to remove with force. I finally broke the white tube after assembling everything back together. I also, check the mother board and switch both cables to notice the error changes from "abnormal Head temperature" to 'abnormal Bed temperature". The bed did not peel apart this time, I did take screen shots of everything and then I notice that the white tubing was short to move the entire length as it suppose to. Now I need another white tubing for the filament to move on all axes...it's not long enough. I upload those screen shots from my phone. This is becoming a little frustrating and time consuming so, bought another 3D printer.
I ordered a Bowden tubing for the Longer’s printer, alone with an extruded tool kit just in case. I downloaded the voltage sheet that you provided and I will test the voltage current running through the printer. Tonight I will set up another 3D printer that I already bought.
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