https://www.sportsrec.com/351318-how-to-troubleshoot-my-reebok-treadmill.html
If the electrical outlet works, unplug the treadmill and check the power cord for damage. Replace the power cord if it's damaged. If the power cord is okay, check the circuit breaker switch on the treadmill and reset the circuit breaker switch if it's tripped.
https://www.searspartsdirect.com/diy/symptom/treadmill-repair/1234711/won-t-power-up/tm520420
Hi, it may be stuck, try and force move the belt safely. if it moves turn it on again and try to start it, Be sure it has power and using the correct cables, make sure the security key is in it, make sure its setup properly without obstruction.
Good Luck
Mr.Mike
https://www.youtube.com/watch?v=a2FCo3JTO00
E02 error code: control board or motor issue. Test the motor first to check if the motor can runing normally. If motor is normal, replace the control board. E03 error code: 1,Turn on the treadmill , motor running a few seconds then stop and console board shows E03, probably the Speed sensor issue.
https://anytreadmillparts.com/pages/treadmill-error-code-troubleshooting
Try to check the Speed sensor. Check for its aliment also check is there is any dust accumulated on it .
If you wish to get some details; check the site linked here. Pull up older posts.
http://electro-medical.blogspot.com/