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For this treadmill, there is a magnetic safety key. When it is removed from the console, the treadmill is safe to leave.
There might also be a breaker switch, which can be reset. If so, it would be near where the power cord goes into the machine. If a rocker switch, turn it to Off, wait a few seconds, turn it to On again, to reset it. If a pushbutton switch, push it in to reset it.
(One might also reset the console or one of its functions.)
Let me know more about what it is, exactly, that you need to know, please, if the above does not answer your question.
What error, or failure-to-work, symptom(s) does it show, please?