Printer randomly stops, Is the power supply bad?

  • I have a prusa i3 with Mendel firmware and a RAMPS board. Recently it has been randomly stopping during prints. The LCD screen will lock up, the print will stop, and the heating elements will turn off. Pressing the reset button on the RAMPS restarts the system and it works fine.

    In addition to stopping during prints, it has also frozen up while just sitting while on.

    My first thought is the power supply (12V 30A) is going bad, but is there anything else I should check before I buy a new one and replace it?


    I replaced the power supply with a new one, and the printer did not stop and completed a print. I am voting to close the question.

    Do you have a multimeter to check what the supply voltage is doing?

    I have measured the voltage on the supply and it is 12V. I am guessing it drops for <1 second which would cause the problem. I am planning on getting a scope and and putting a trigger on the voltage and also measuring current out of the supply.

    Are you confident that your mains power is stable? If you have a spare UPS unit or one you can temporarily assign to the printer, using it will eliminate or confirm problems with commercial power, as opposed to on-board power supply trouble.

    I'm a little suspicious about the PSU being the issue here, because locking up implies the processor froze, and the processor is on a 5v regulator circuit that should be pretty resistant to input voltage variation.

    As an add-up to Ryans comment: If the voltage drops below operation level (as in the case of complete loss of power for a short time), the board should not freeze but simply restart as soon as power is back (not 100% sure, correct me if any of you have experience with too low voltage)

  • It could be several things.

    Your ramps board is overheating or has to much load on it. If you're not cooling the ramps board adding a fan may help the issue.

    I know Robo3D had this issue and started shipping with a fan to cool the ramps board.

    The ramps/arduino board could be faulty, the firmware may have gotten corrupted or the current version has a bug in the code.

    If you are not printing from the sdcard on the lcd controller and using software through a usb connection, that computer may be causing the issue as well.

    for anyone who could be interested in cooling ramps

  • I had the same thing, the printer was not heating the nozzle anymore after starting the print. I fixed this by reinstalling the firmware.

    It could also be that your stepper drivers are overheating. you can add a fan to cool them.

    The SD card could be bad, maybe try an other card or another .gcode file.

    It is probably not your power supply, a 30A power supply is more than enough, but you can measure the volts on the power supply while the printer is running, if it is around 12V it is probably alright.

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