Heater Fault Troubleshooting

[jgbowman]

@dc42 I updated all of my firmware to 1.21 and this successfully switched the setting from x-axis to z-axis. Only thing is that I now get this error when trying to manually probe the z-axis.

[dc42]

For now you will need to add command M564 H0 to config.g to allow movement of an axis before it is homed. This will be fixed in future firmware and DWC revisions.

[jgbowman]

@dc42 I added it here, but I'm still getting the same result.

[dc42]

Odd, that should have fixed it. Please run M564 without parameters and see whether it says movement is allowed when the axis concerned is not homed.

[mrehorstdmd]

@jgbowman

Where did you get the PT100 sensor? More importantly, what is the insulation material on the leads?

I recently tried to use some cheapo PT100 sensors with teflon insulation on the leads and after a couple weeks of occasional ABS printing I started getting the same sort of weird heater faults you did, including the spikes to 2k. I checked the resistance between the PT100 leads and the metal casing and found that one of the leads shorted to the case. The case is in contact with the heater block, which in my printer is grounded.

Swapping in a new PT100 sensor will fix the problem temporarily, until the teflon wire insulation inside the sensor housing breaks down due to the high temperature.

Teflon insulation going into the metal sensor housing is a no-go for high temperature use. The E3D PT100 sensor has fiberglass insulation which should be reliable at high temperatures.

[jgbowman]

@dc42 It says movement before homing is not permitted. All of the firmware is updated to 1.21 except for the paneldue, could that be the problem?

[jgbowman]

@mrehorstdmd Not sure where my boss got the sensors, but I've tried to switch out a couple of them, so i'm pretty sure it's either a wiring or configuration issue. I ordered a new daughterboard because that seems like the most likely fix. For now i have got it working with regular thermistors though.

[mrehorstdmd]

@jgbowman

Do they have Teflon insulation on the wires?

[jgbowman]

@mrehorstdmd i believe so

[mrehorstdmd]

@jgbowman

Teflon breaks down at ABS print temperatures. If the Teflon breaks down inside the casing, it will short to the case and that will cause erratic behavior. Check the resistance between the wires and the metal casing of the sensor- any noninfinite reading is bad.

I had the same problem a week ago. Swapping in a new PT100 of the same type will fix it temporarily, until the Teflon breaks down.

PT100 sensors that are going to be used in the hot-end should have fiberglass insulation on the leads. E3D's PT100 sensor does.

[jgbowman]

@mrehorstdmd Thank you, although switching out the pt100s doesn't even temporarily fix the problem for me, so I'm sure i'm having another issue. Will definitely look into the E3D sensors though.

[dc42]

@jgbowman said in Heater Fault Troubleshooting:

@dc42 It says movement before homing is not permitted.

Then the M564 H0 command in config.g isn't working. Try retyping it.

[jgbowman]

@dc42 I tried moving it around a bit, but to no effect. Even though I put 1.20 and later in the configuration settings, config.g still says 1.17-1.19. Could this have something to do with my issues?

[T3P3Tony]

@jgbowman the header at the top of config.g is just a comment written by the configurator.

If you go into the gcode console screen and type M564 H0, send that and then type M564. What does it report?

[jgbowman]

@t3p3tony That got it working, thank you

[T3P3Tony]

@jgbowman ok thats interesting. So it works is entered directly, but not in config.g? Maybe try a reboot with it in config.g and see if it continues to work after the reboot.