Test print

I’ve tried doing a test print this afternoon. it keeps stopping with an error about thermal runaway. Can someone enlighten me as to whats wrong?

Any more specs on your setup?

That means you are not getting too or holding the temps well enough.

Power supply size or quality, thermistor, ridiculous temps set, AC running, fan, near a window, loose wire?

The lcd screen was showing that the temp was OK. My 1st thought was a loose wire so double checked all wiring all seemed OK. Power supply was a 12v 6 amp type for led lighting etc.

Did you flash the firmware to enable the Thermistors “EB”? The stock one has the dummy value hard coded to 170C.




I flashed this one.


I assume that this is the latest version for 8mm threaded rod?

Power supply, board, extruder, thermistor, bed, temps?


I really can’t help without a bunch more info. A picture might help as well.

Hi ryan,

Thanks for helping. The board is a ramps 1.4 bought as a complete kit from ebay. The extruder was purchased along with the wiring harness from yourself. I don’t have a heated bed as I was of the understanding that for pla you don’t actually need one. the extruder was set to a temp of 200 as set up in your settings for Repetier Host from your site.

It was in this software that I was trying to do the test print this afternoon.

Does it get hot at all? I am really unclear to what is actually happening.

Power supply?

CNC stuff is super easy to know what is going on, 3D printing you have to give me all the details. Stabbing in the dark is not fun. Power supply failing, thermistor coming out of the head, doe it heat at all does it over heat, fan?

Switch Repetier-Host to display the temperature and see if you’re getting a dip on the hot end. It can happen with drafts or a misaligned fan. A drop of a degree or two that doesn’t recover quickly will generate that error.

IIRC, repetier host has a recent temp graph. Octoprint does too. I think they both keep about 15 minutes of history. The graph tells you so much more than a number.

Repetier-Host keeps 60 minutes of temperature history. You can scale in and out and will want to zoom all the way in for this type of error.