Power Devil is owned by Alba Radio LTD.
There are no parts lists available, or spare parts for that matter.
They are fairly easy to check with a multimeter, first check the cable, switch, and for continuity across the brushes, through the armature.
Unless you can find a donor machine for spares, or it is a cable fault, you will not be able to repair this.
Hope this helps.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix circular saws.