Sudden Loss of Power

I ran a cut this morning to flatten my spoil board and everything went fine. Then I went up to woodcraft to pick up a bit to run a cut I was planning to do and when I came back I noticed the board was off and would not power back on. After my spoil board flattening I did vacuum and use my air compressor to blow off dust so there is a chance I moved something that shouldn’t have been moved. I’m attaching pictures of my board. Can you please take a look at it and see if maybe I’m missing a jumper or something along those lines? Thank you.

I notice you’re using the barrel plug adapter which generally isn’t recommended as it’s known to sometimes cause problems. You might want to eliminate it and run power directly to the board.


Using a multimeter, you need to trace the power to locate the problem. Check:

  • Output of the power supply. We’ve seen problems like yours that trace to a failed power supply.
  • Power input at the board at the screw connections. If the power does not make it to the screw connections, then Paul’s suggestion is a way to fix the problem
  • 12V power pins (photo below). These are on the 12V motor rail.
  • Any 5V pin/ground pair on the board.
  • If power makes it to the screw connections but not beyond, check the F2 and F3 fuses. The F4 fuse is used for the heated bed and is not used for the MPCNC.

There is a 12V pin pair on the motor rail located inside the blue rectangle in this image:

I have power at the screw terminals and at the blue rectangle you showed in the image. I don’t know where there is a 5v to check but everything seems ok as far as I can tell. No LED activity on the board and no activity on the LCD screen either. Any other ideas?

I must have been misreading what I saw on the multimeter. You guys were right, it was the barrel adapter. I hooked it up to my desktop power supply and it’s working fine now. Thank you for your help. I really appreciate it.

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