Temperature never stabilizes

I went to print something today and suddenly I realized that the printer never gave the “OK” signal to start printing. I’m watching the nozzle temperature and it is hopping up and down 5-10 degrees at a time and never stabilizes.

Then I went to the snapmaker store to try to buy a new thermistor and heater tube and there’s no way to send it to Norway.

I also checked the USB port with a tester and when I plug in the usb key that came with the snapmaker, the voltage drops to 4.3V. I’m wondering if there’s something wrong with the voltage regulation on the controller.

Anyone have any ideas??

Hi erics84
Did the fan inside the 3D print module working fine?

Yes the fans appear to be working fine. When I plug something into the USB socket, I notice the measured temperature of the nozzle drops about 10 degrees and sometimes goes negative!

I see.
Seems like the hot-end couldn’t keep the temperature stabilizing.

It’s hard to say the nozzle temperature was only effected by the voltage on the controller.

Did the nozzle temperature got N/A before? It seems like the thermistor may be not working fine.

You can check this thread http://forum.snapmaker.com/t/troubleshooting/155/186 . There’s a similar case like yours, you can check this first.

Hope this can help you.

I see I’ve forgotten to respond here. I’ve been using my Snapmaker with this problem successfully for years, but with a caveat. The temperature never stabilizes enough to start printing, I’m thinking something is physically damaged on the controller board because I have switched the entire hot end out.

Anyway, to get around this, I changed to Cura and set up an auto post-processing script to replace M190 with M140 and M109 with M104. The only problem with this is that I have to manually start heating before printing or else it will try to extrude cold.