Hi, my mini2 had been printing fine for months, but then began having the following error even though I had not changed anything: “Err: MINTEMP: Bed PRINTER HLATED Please Reset”. This usually occurs about 30 minutes into a print, and the layers are coming out totally fine when this happens. When I reset immediately, the tool head is still at 190°C or so, and the print bed has reach 65°C. I replaced the entire printed bed heating module, and it worked only for one print before the error began occurring again. Not sure what more to troubleshoot.
What should the bed temp have been? 60c, 100c?
Were you printing off SD card or USB to a computer/octoprint? If it’s on the computer or through octoprint, what was the reported temperature doing before the error?
My guess would be a bad connection on the circuit for the bed thermistor, so either a bad connection in the harness, break in the wires, or loose connection to the controller board.
I was printing of an SD but connecting through the computer is good idea to read in the error codes. The bed was supposed to be at 60°C. I’ll snake through all the wires to find any broken ones.
If it’s hotter than it should be, the board is getting a low reading, then it tries to compensate by heating the bed. This is a potential thermal runaway event that could lead to a fire. Absolutely don’t run this machine unattended.
If it’s a failing wire, you might be able to find it out safely by just manually moving the wires and bed while watching the bed temperature on the display. If it ever drops from ambient temp down to 0, you know there’s a break in the wire there.