When we use an FDM 3D printer to print something and preheat goes, sometimes MINTEMP or MINTEMP BED error appears on the screen unexpectedly and the printer halted. Then why is it happening and how can we fix it? Let’s start by understanding the problem with Anet A8 Plus.
Err: MINTEMP on Anet A8 Plus 3D Printer
What is MINTEMP or MINTEMP BED Error?
MINTEMP error indicates temperature readout problem on hot end (nozzle) thermistor and MINTEMP BED error indicates temperature readout problem on hotbed thermistor. In these situations, the printer will notice MINTEMP or MINTEMP BED error and halt to prevent overheating on the hot end or the hotbed. Usually, before the printer halt, we can observe the temperature of the hot end or the hotbed increases or decreases a lot when the Y-axis or X-axis moves.
How to fix NIMTEMP or MINTEMP BED Error?
Sometimes, the error is caused by a sudden glitch or breeze, or even when you use the printer under the air conditioner’s air outlet, and the LCD will notice “MINTEMP Fixed” or “MINTEMP BED Fixed”. In these conditions, we only need to restart the printer and see if the printer works properly. If NIMTEMP or NIMTEMP BED error appears on the screen again, then we should further check the hot end or the hotbed thermistor if they’re well connected or work well.
Step 1 Check Thermistor Connection
Check thermistor connection on hot end or hotbed accordingly.
If they’re well connected, go to next step.
If not, reconnect them and check again if the printer operates well; if the printer still halts with the same error, go to the next step.
Step 2 Measure Hot End and Thermistor Resistance
Use a multimeter to measure hot end or hotbed thermistor resistance out accordingly.
Note: This should be done at room temperature. Too low or high temperature will affect the result.
Method for hot end thermistor resistance measuring:
Switch the multimeter to resistance measurement and place its two probes onto the TMP labeled wiring pins to measure the hot end thermistor resistance.
Hot end thermistor resistance value of anet et4 pro
Method for hotbed thermistor resistance measuring:
Switch the multimeter to resistance measurement and place its two probes onto the two middle pins (not the side pins) of the 6-pin plug (hotbed to mainboard plug) to measure out the hotbed thermistor resistance.
Normally, the resistances for both the hot end and hotbed thermistor should be between 70 -100KΩ, and can vary a little (as we mentioned above and see above test result for reference) according to ambient temperature. If one of these values has a huge offset, then we need to replace the thermistor accordingly.
But for Anet 3D printer, the hotbed thermistor is pre-installed onto the hotbed, and to replace it you need to change a new hotbed.
In conclusion, MINTEMP and MINTEMP BED errors are quite common problems happen on desktop FDM 3D printer. If it occurs, we need to check the thermistor connection and measure if the thermistor has appropriate resistance to avoid the printer not reading out the temperature. To fix the problem, we can reconnect or replace the hot end or hotbed thermistor according to different conditions.