Power Issues - Low Voltage off PSU


I got a kit recently and have it all assembled, I managed to get a few print runs going and recently have had a lot of trouble when printing long prints or printing at higher temperatures. Which has caused a lot of fun getting stable prints.

I have adjusted the vref on my motors to 0.43 V and the Z-Axis a little higher (was stalling at 4.3 here). However my PSU is only putting out ~11.5V, and dips way down during load. The potentiometer is maxed. My understanding is that it shouldn’t have to be maxed to put out the 12v.

My print fan will also not run, but will run plugged into the cooling fan area for the board. I’ll be checking this tonight.

Should I reach out to Marty for a replacement or am I missing something?


I had two similar issues:

  1. Make sure your fans are plugged in correctly +/-. I had the extruder fan wires reversed and didn’t find it for months - until I built my second printer.

  2. I gave up on the power supplies. I modified two Corsair PC power supplies and finally my heat beds maintain temperature and everything works.


I figured out the fan issue: My ground pin on the fan is not soldered to the board. So easy fix.

The PSU thing, yeah I’ll keep investigating.


I youtubed how to use a PC PSU. My heated bed would not maintain temperature and I was using a heat gun with cardboard coated in foil to get it to heat.