Original Prusa Mini+ Kit - "TEMP NOT MATCHING" Error
I wanted to open this topic to see if others had the same problem or if there is a fix or corrective action.
After assembling the Mini+ kit and performing all tests and leveling I began to print the tree frog with the included filament. Once that had completed I attempted to load PETG filament and then the problem began. I would receive the error "TEMP NOT MATCHING", "Measured temperature is not matching expected value. Check the thermistor is in contact with hotend. In case of damage, replace it."
I looked into the forums and bug lists and found this blurb within the FW 4.4.0 release notes: "Note that this safety feature is currently still in beta and might misbehave. The algorithm is expecting a stock MINI+ printer, without any hardware interventions. Should you encounter any issue, please report it to our developers using GitHub."
I went ahead and opened a bug on the topic to allow for a reported case of the occurrence. The Bug #2993 was created.
I will upgrade to the latest FW 4.4.1 today and see if the problem persists.
Machine Details
Printer type - [MINI]
Printer firmware version - [4.4.0+4180]
Original or Custom firmware - [Original]
Optional upgrades - [Texture Build Plate]
USB drive or USB/Octoprint - [USB]
How to reproduce - placed the hotend temperature at 240 degrees and only after a minute the error message is shown. This happens each time I attempt to print or test the thermistor.
Expected behavior - The expected behavior is the hotend heats to set temperature and does not shut off.
Best Answer by Chris Barnes:
The support desk has been very helpful. I actually stumbled onto the problem while taking measurement to provide to the help desk. The thermistor in the preassembled hotend had been crushed from the factory. Maybe crushed is too strong of a word. The grub screw for the thermistor was overtightened and it was pushing too hard. The result is in the image HERE.
RE: Original Prusa Mini+ Kit - "TEMP NOT MATCHING" Error
I have finished upgrading to FW 4.4.1 and the issue still remains.
RE: Original Prusa Mini+ Kit - "TEMP NOT MATCHING" Error
There are actually several tickets already open on Github on that very topic. Clearly, this was rolled out way too prematurely. And unlike on the Mk3S, with the Mini there's no way to disable it permanently. In my case, I get the warning the first time I load filament, then never again. Even if I let the hotend cool down to room temp and start a new print from there.
I got the runaround about making sure you're using original parts etc. (which I do), check everything is properly seated (which it is), but the fact that I get the error only on the first load is a clear sign to me that it has nothing to do with thermistor or heater.
My workaround: Before I load filament for the first time after a reboot, I manually heat the nozzle to 175 degrees. IF I do that, the load filament procedure will succeed without an error. But obviously, YMMV.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE:
I had the same error in January. Prusa customer support helped identify that it was the hot end thermistor... But it also manifested when the pla filament started to print. It would start printing but you could tell that filament kept on getting hotter and hotter until the error popped up. This would occur pretty quickly.
We tested the thermistor with the multimeter for resistance. Additionally, we moved the cords around while testing.
I have a partially assembled mini +
When I replaced the Thermistor, it appeared a piece of the metal had broken off the bulb portion.
RE: Original Prusa Mini+ Kit - "TEMP NOT MATCHING" Error
is this a glitch where it says 53 years ago 🙂
Please help me out by downloading a model it's free and easy but really helps me out https://www.printables.com/@Hello_474427/models
RE: Original Prusa Mini+ Kit - "TEMP NOT MATCHING" Error
It's gone now because I just posted
Please help me out by downloading a model it's free and easy but really helps me out https://www.printables.com/@Hello_474427/models
RE: Original Prusa Mini+ Kit - "TEMP NOT MATCHING" Error
@Hello - Well I am approaching that age .....
What I find interesting is several tickets were opened with different solutions. I followed their guidance and opened a bug to hopefully fix the issue or remove it altogether for now.
RE: Original Prusa Mini+ Kit - "TEMP NOT MATCHING" Error
Ok, as always the Prusa team is on the Case. We have verified and isolated components for testing all tests appear to be within normal ranges. Will update once we find my solution.
Found the problem.
The support desk has been very helpful. I actually stumbled onto the problem while taking measurement to provide to the help desk. The thermistor in the preassembled hotend had been crushed from the factory. Maybe crushed is too strong of a word. The grub screw for the thermistor was overtightened and it was pushing too hard. The result is in the image HERE.
RE: Original Prusa Mini+ Kit - "TEMP NOT MATCHING" Error
@chris-barnes so any update here? I am getting the issue with a Dragon hotend which I would really like to use.
Ok, as always the Prusa team is on the Case. We have verified and isolated components for testing all tests appear to be within normal ranges. Will update once we find my solution.