Hot end doesn't heat up after Hot end change out. Constant Thermal Anomaly alarm. Im so frustrated
My wife got me a Prusa I3 Mk3s about a month ago and, after a learning curve, it was great. I noticed that it was getting globby and not printing well and so I checked the nozzle and it was pretty old and beat up (Its a used printer). No I went to change the nozzle (0.4mm) and bam, the brass nozzle breaks off inside. Well, Im not getting that out so I decide to change the block, but everything is stuck. I cant get the Heating element out, the Thermistor out..so I decide to just replace the whole hote end and element. plug and play, it should be easy right? I go to Amazon and get a 24V Hot end kit and all the elements and wiring. I install it on the board, get it all situated and it works....for a day. then the Thermal Anomaly alarm starts going off. Ok, I take it apart and put it all back together, I check all connections and all is well. Still doing it. I change it out again. all wiring and everything. Now, it wont even heat up. it stops me on the self test and preheat. I flashed it and reinstalled the newest firmware, I made sure the connections on the board was right. I tried to calibrate, but im stopped instantly . I really want to use my present, but I cannot at this point. I try and go to all the forums but all I can find is "replace" and thats what I have done. Im going to replace the fuses tonight as my last guess. Please help with this.
RE: Hot end doesn't heat up after Hot end change out. Constant Thermal Anomaly alarm. Im so frustrated
You could install 3.11 firmware which doesn’t check for thermal state. Now you might have a real hardware issue, but this might get u printing. I’ve never updated because of the number of users complaining they were getting thermal error messages in latest versions
RE: Hot end doesn't heat up after Hot end change out. Constant Thermal Anomaly alarm. Im so frustrated
Hello shadower360, sorry to hear about your frustration.
To replace nozzles, the hot end needs to be at an filament operating temperature due to metal expansion as it heats. If you have the block out, you need to heat it to separate the various parts. I just rebuilt my head last week due to missing the working temperature setting for nozzle changes. I had a small leak when I started to print with ASA as the nozzle was tightened at a lower temperature and leaked at the higher temperature. If you put the block in a vice, you can heat it up with a paint stripper gun or carefully with a small blowtorch. Once you get the heat break out, I have used a screwdriver to get the broken nozzle out while keeping the block heated. To get the resistor and heating element out of the aluminium block, I had to remove the two set screws and use a pin punch and small hammer. Not something you can do when it is mounted.
Did you run the thermal calibration? That is very important. I had issues until I ran the calibration when it first came out. I have had one alarm since then.
If you have an ohm meter, measure the resistance from the heater element and the resistor. It is easy to break or damage the leads. Heating element should be about 14 ohms. Thermistor about 100 ohms. You only have to unplug them from the circuit board. I also noticed that it is possible to short the heater leads out if the insulator slides up the wire. You can check if the thermistor is working using a hair drier and watching the display if the temperature goes up.
FWIW, I ordered some cheap spare heaters online that were supposed to be 24V but are 12V.
RE: Hot end doesn't heat up after Hot end change out. Constant Thermal Anomaly alarm. Im so frustrated
Update.
I reflashed to an earlier version_ same alarm and shut down. Neither the Bed nor the block heat up. I know the Thermistor works, because I used a heat gun and it showed the temp went up. I'm starting to think its one of two things. either there's a blown fuse or the board is FUBAR
RE: Hot end doesn't heat up after Hot end change out. Constant Thermal Anomaly alarm. Im so frustrated
Fuses are easy to check.
If a fuse blows, it is an indication of a short somehow. Same with board burning out. I came across this link earlier today and may be useful.
If the board is damaged beyond repair, I would look at doing one of the major upgrades with the 32 bit boards for the better experience.
RE: Hot end doesn't heat up after Hot end change out. Constant Thermal Anomaly alarm. Im so frustrated
Prusa's help for blown-fuse-mk3-mk3s. I'd buy critical parts from a decent supplier if not directly from Prusa.
changing-or-replacing-the-nozzle: In the drawing, please note the gap between heatblock and nozzle hexagonal head. Use a torque screw driver (2.5 Nm) if available.
how-to-replace-a-heatbreak-heatsink-heaterblock : On my MK3S+ I hardly ever unscrew the nozzle. I have a hard coated brass nozzle, titanium heat break and a nickel plated copper heat block (E3D).
If you print PLA in a warm environment, heat creep might be an issue: extrusion-stopped-mid-print-heat-creep, clogged-nozzle-hotend, Then you hear the extruder clicking. The slightly changed plastic parts of the MK3S+ extruder mitigate that. The filament path inside was improved. The hotend-ptfe-tube has a different length. Please do not change too much at a time though. "Baby steps."
Once you get your printer up and running again watch out for a filament dryer. And the satin-steel sheet if you do not yet own it.