## Anet A8 ignores extruder temperature?

3

I don't understand what's wrong with my G-code. I have set the printing temperature to 195 °C but when I try to print, the target temperature is always 0 °C and printing never starts.

I have tried changing material preset to different PLA profiles but that didn't help at all.

G-code:

;FLAVOR:RepRap
;TIME:1736
;Filament used: 0.676205m
;Layer height: 0.1
;Generated with Cura_SteamEngine 3.4.1
T0
M190 S50
M104 S195
M109 S195
M82 ;absolute extrusion mode
G21 ;metric values
G90 ;absolute positioning
M82 ;set extruder to absolute mode
G28 X0 Y0 ;move X/Y to min endstops
G28 Z0 ;move Z to min endstops
G1 Z15.0 F9000 ;move the platform down 15mm
G92 E0 ;zero the extruded length
G1 F200 E3 ;extrude 3mm of feed stock
G92 E0 ;zero the extruded length again
G1 F9000
M117 Print0ng...
M83 ;relative extrusion mode
G1 F1500 E-6.5
;LAYER_COUNT:96
;LAYER:0
M107
G0 F600 X90.425 Y93.152 Z0.3
;TYPE:SKIRT
G1 F1500 E6.5
...


In addition, the extruder and heat sensor are working. An older G-code file correctly sets 200 °C as the target temperature for the extruder.

This G-code prints just fine

;FLAVOR:RepRap
;TIME:4628
;Filament used: 1.44191m
;Layer height: 0.15
;Generated with Cura_SteamEngine 3.4.1
T0
M190 S60
M104 S200
M109 S200
M82 ;absolute extrusion mode
G21 ;metric values
G90 ;absolute positioning
M82 ;set extruder to absolute mode
G28 X0 Y0 ;move X/Y to min endstops
G28 Z0 ;move Z to min endstops
G1 Z15.0 F9000 ;move the platform down 15mm
G92 E0 ;zero the extruded length
G1 F200 E3 ;extrude 3mm of feed stock
G92 E0 ;zero the extruded length again
G1 F9000
M117 Print0ng...
M83 ;relative extrusion mode
G1 F1500 E-6.5
;LAYER_COUNT:80
;LAYER:0
M107
G0 F4800 X72.96 Y99.484 Z0.3
;TYPE:SKIRT
---


Note, I have never modified the firmware or changed anything except what I can change with the frontpanel.

What do you mean by "Target temperature" --> the displayed value on the screen? Will the extruder start to move if you edit your code to M104 S0 M109 S0 ? Have you tried more recent versions of Cura? Oh, and what printer are you using, what firmware, etc.? – Carl Witthoft – 2019-02-12T16:08:01.343

No, the extruder reads 25/0 on the A8 screen. As said in title, I have an Anet A8 printer. Target temperature is the temperature the extruder should reach before printing. – user6329530 – 2019-02-12T17:32:09.293

For troubleshooting further, I suggest to connect to the printer directly (What is a printer console/terminal?) and send M104 S200 or use the UI to set these. We also could help you in [chat] further.

– Trish – 2019-11-06T13:59:09.427

2

I got the same problem today and after a lot of troubleshooting (following the answers here) I found out that the issue was the connection to the hotbed. After I clean out the connection to the hotbed the printer started working as usual. The debugging logic was that the printer heats up the hotbed before setting the extruder temperature.

Looking to your LCD the issue seems to be the same, since 33 degrees is a normal ambient temperature.

2

There is nothing wrong with the G-code, M109 S195 sets and waits for the temperature to reach the set point. There must be a different reason, other than G-code, why the temperature is not set correctly.

After updating your question by adding another G-code script, the conclusion is that there is nothing wrong with the G-code itself. The problem is that the printer cannot set the 195 °C temperature.

Could it be that the minimum temperature is 200 °C and that it doesn't set a temperature lower than the minimum value?

If you are comfortable enough to flash a new firmware (which you should always do with an Anet A8 as it has no thermal runaway protection) you could try to see if this is a firmware problem.

The thermistor is working, it's reading room temperature. The display shows 25 / 0 °C. The target temperature is wrong (0°C). – user6329530 – 2019-02-12T17:33:07.137

I never had any problem with lower temperature. I can try to set the temperature in Cura to 200 but I know that I printed with 195°C before. – user6329530 – 2019-02-13T06:09:11.270

I have now loaded a gcode that has 200°C as target temperature and it shows 0° as well. As another test, I copied the starting gcode of the working file to the file that doesnt work and it still shows 0° ... I am out of ideas now on what to try. – user6329530 – 2019-02-13T11:15:39.567

1@user6329530 sure looks like a flaky control board, leading to intermittent errors. Just in case, clean and re-engage every connector -- especially the thermistor and heater cables. – Carl Witthoft – 2019-02-13T15:29:33.483

How can that be a flanky control boad when the one gcode works and the other doesn't... where is the difference? – user6329530 – 2019-02-13T18:26:44.920

@user6329530 I thought you wrote that you retried a working file and it failed. if that's not the case, then you may need to look at your gcode files in a good text editor and look for invisible (but bad) characters – Carl Witthoft – 2019-02-14T16:18:01.983

Yeah that's what I was trying to say. I wonder why one gcode works and the other wont. I loaded the same model into Slic3r and had the same result (0° target). That's why I am lost. I can print the thing when I set the extruder temp to a fixed value in the control pannel but that results in overextrusion... – user6329530 – 2019-02-14T17:07:09.763

1

Double check the physical connection to the heating element and the thermistor that go in the hot end. Those wires and crimps aren't great. I had one fail on me out of the box with my A8. Re-crimping did the trick.

1

Be sure that you are using the version of Cura (14.07) that comes on the SD card provided with the printer. I ran into this same thing after updating Cura, largely because it prompts you to when it starts.

1

You don't mention printing via a connected computer over USB, so I assume you're printing from an SD card. I think the most likely cause of your problem is a corrupted filesystem on the SD card, or bad SD card. I've had many occasions where my printer (Ender 3 with Marlin, stock and upgraded to 2.0) fails to see files or correctly read files despite them being readable when the SD card is put in a PC; I suspect the microcontroller library implementations of FAT filesystem reading are less tolerant of errors than real filesystem drivers on Windows, Linux, etc.

Try backing up all the files you care about on the SD card, reformatting it, and repopulting it with known-good files and see if the problem goes away.