Hi all Most times when I startup the printer, it shows the Error: Err: MINTEMP BED This is preventing me from doing anything. I can't find the issue, checked all the cables. The connection on the rumba seems a little loose, but since it works from time to time, I'm not sure, what to do or where to look. Do you guys have any idea what I could try to solve this issue? Thanks so much!
what is the displayed temp reading for the bed when you start up ? If the reading is below 5 and your workshop isn't in a refrigerator then you have a wiring fault to the bed thermistor or a bad thermistor.
I can confirm, my workspace is not in a refrigerator. When the error is occouring, there is no temperature read whatsoever. It behaves like it does, when the whole PCB is not connected at all. Looks like: But sometimes, when everything works fine, it shows temperatures which are realistic, as far as I see (23° for the hotend / 22° for the PCB). Looks like:
From what you describe you have to kind of connection problem to the temp sensor of the bed. Check if the connector sits tight on the PINs if the RUMBA by moving the connector slightly and check if the temperature reading is still active. I had problems with one of the fan connectors. Pushing it a bit to the left and it lost contact. If your cable connection is fine check the conduction/resistance of the both sensor cables with a multimeter. At last if that all is ok it might be the connector on the bed. If it works then does not work it could be a problem with the solder joint. In that case you better contact support...
Yeah your thermistor is loose. Check all your connections to start. Then start measuring the resistance to find the 100kohm resistance from the bed and that it's making it's way back to the rumba
Well, I tried to locate the issue a little bit further. Once the machine was working properly I checked the connections by moving them until the error occoured. It was the case, once I wobbled the connector on the bed itself. After that I removed the connector and checked it for obvious issues. I found nothing and connected it again. Since then, it is much better. I'll have an eye on that and will try to measure like @Mike Kelly described. Thanks for your tips!