Have just finished building K8200 printer everything working apart from the heated bed.
With everything connected there was no entry in the bottom status bar of Repetier and manual control area showed 0 degrees. Extruder showed 19.2 degrees. Clicking the on button gave no change and no LED light. Placing my hand on the bed caused the reading to raise to 1.9 shown in manual control and status bar.
Changing the heat bed and extruder connections over enabled the bed to work correctly, although controlled by the extruder button.
Changing the connections back to correct positions (while bed still hot) enabled the bed to work, but the display showed a way lower temperature
Then allowing the bed to cool down to room temperature returned it back to not being able to heat up
Please advise of possible causes and remedies
please recheck the wiring of the bed thermistor. Measure the resistance at the (disconnected) plug at room temperature. Do you get a value in the range of 100 kΩ, say between 80 and 120?
If the temperature is indicated as 0 °C, that usually means that the connection to the thermistor is broken. Since in your case there was a minimal change possible, the connection seems to be not totally gone, but very limited.
Should you measure a wrong resistance value, check the wires and also the solder joints of the thermistor itself and the connection between wires and heater PCB.
An error on the controller board is also possible, but it’s a bit unclear to me which connectors you changed (heating elements or thermistors) and to what end. In case the thermistor is ok, having a look back at this would be the next step.
108 at the plug.
I changed both connectors on the PCB so the bed was connected as if it was the extruder and the bed worked correctly, i.e heating up to the required temperature and showing the correct temperature, so I think the wiring and thermistor are all working properly
Thanks for the reply
108 at the plug.
I changed both connectors on the PCB so the bed was connected as if it was the extruder and the bed worked correctly, i.e heating up to the required temperature and showing the correct temperature, so I think the wiring and thermistor are all working properly
if the thermistor’s resistance is ok and the board still shows wrong values, this unfortunately points to an error on the controller board, e.g. a faulty AD converter in the ATmega. There’s only a tiny possibility for a successful repair at home, and additionally it would void your warranty. The better way is to contact the Velleman support deptartment about this issue. Let them know which country you’re from, there are different procedures for Europe and US.