There’s a tutorial for machines which don’t run at speeds over 1.800rph due to low voltage output from the electricity network. It is on Mark VII’s website, find it and it will show you how to open the electronics console and where the switch is. VERY easy! One of the extremes is 110v, the other one is for 220v and the one in the middle is for mediocre electricity output from developing countries like the one I live in.