Heated bed is not heating anymore

  • I have built a RepRap Prusa i2 a while back. It worked for a while, but then I moved the printer from place to place and after a while I noticed that the printer's bed is not heating anymore. The thermistor shows the temperature (room temperature), but the bed is not heating.
    The wires are connected and the heated bed has a resistance.



    Did anyone else confronted with this? Thanks!


    Do some probing around with a multimeter. Is there voltage across the beds inputs, check for continuity in the wires, etc...

  • StarWind0

    StarWind0 Correct answer

    5 years ago

    diagnosing a heated bed


    Switch the hot end and the heater bed wires on the board. See if there is a difference. (Note that it will not reach a thermal limit when plugged in this way! So don't leave it on too long!)


    After that, if you see that your heat increases with the hot end's wires and the hot end being set on in software then you know the issue is likely with the board. At which point try updating / reflashing the board.


    Alternatively, you can try a second board and see if it makes a difference.


    If the bed does not heat up even using the heater cartridge connectors, then your heated build plate likely needs to be replaced. Or the wire needs to be replaced.


    If you are running Ramps or a board that uses 2 hot end outputs you can likely reprogram it to use hot end heater 2 as the new output for your heated bed.


    using a hot end heater output on the electronics to heat a heated bed could damage the electronics. It is probably not a problem for a short test but definitely not a long time solution!. This is very dangerous. The heated bed draws a much higher current than the hot end. This could damage the electronics, melt the connectors or even start a fire!

    The test is correct switching the heatbed to the nozzle heater, just be careful to set the temperature for 50° as maximum to not burn the heatbed. The electronics can support this changes.

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Content dated before 7/24/2021 11:53 AM

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