What fuse should be fitted in the power cable. I have a multitude of these cables. Some have 5A already in, some 13A. Which to use? I'm just at the part of the build prior to the power on test and stepper motor tuning. Thus I'm quite nervous. I have a dual and still have half the wires (for the left extruder) unplugged. A quick scout through the instructions doesn't help and I can't find the point in Livi's videos where this is dicussed (I think she just breezes through this, partly from experience and possibly because there was no manual at this stage. So, any input here would be much appreciated. Should I turn it on and tune just half the print head? My RUMBA board connections look exactly as they should on the photo immediate prior to the power on test in the manual.