Spirit treadmill dead, no power at all, what's the usual culprit?

For Spirit treadmills the order is outlet (non-contact tester), power cord at both ends, rocker switch with a continuity tester, then the safety key. If all that fails then the inline fuse on the lower deck for XT/CT models, the thermal reset on the motor for XT685 model, or the lower board itself.
Spirit treadmills are some of the most well built treadmills on the market so when they do develop an issue it’s usually the cheaper parts that fail first.
 
For Spirit treadmills the order is outlet (non-contact tester), power cord at both ends, rocker switch with a continuity tester, then the safety key. If all that fails then the inline fuse on the lower deck for XT/CT models, the thermal reset on the motor for XT685 model, or the …

sole bashing is unwarranted, my f80 has been running 9 years no issues
 
ok ordered a multimeter, what should I test first when it gets here

outlet first with the probes in the power slots. Should read 120 or so. Then unplug treadmill and test the power cord itself. Then the rocker switch. Work from the electrical outlet towards the lower board.
 
the fuse in the power plug is another common one on UK treadmills. I helped my brother in law troubleshoot his for like 2 hours over the phone before I realized it was just a 50p fuse in the power plug. He was ready to bin the treadmill.