Bed Not Heating



  • So I have an Ender 2 that the board stopped working on - guessing the mosfet blew and ended up burning the bed connector at the bed slightly. I checked the bed and it has continuity all the way though the connector. I also checked the resistance and it's 1.2-1.4 ohm. I can put it directly to the 12v power supply and it heats up fine, and with the temp probe connected to the Duet, it increases and reads the right temp. Bed seems good.

    When connected to the Duet Wifi 1.02, the bed heater LED lights, but the temperature never rises. I verify that I'm getting 12v at the bed connectors when the heater circuit is running.

    Any thoughts on what it could be?



  • The circuit switches te ground connection, not the 12V. Test the voltage on the ground lead. If you see 12V with the heater supposedly on then you do not get power to the bed. With the heater on, you should see a very low voltage on the ground pin.
    Check the fuses and visually check the fet transistor. Is it discoloured? Does it have a small chunk missing out of the case ?



  • Indeed it was the ground pin on the bed side. At some point the connector was lose and I had to bend the internal tab down to make better connection.



  • I am not sure what you are saying but hopefully you are saying that the issue arose from a poor ground connection and all is well now.


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