I would suggest that you turn Off and unplug the machine, dismount the console from its mountings, remove its back case, and remove, then re-seat, the cable connectors.
Then put the case back on, mount the console again, and try the machine again.
If that doesn't help, then your console may need replacing, esp. if there's not other problem with anything it controls, while it is working. Or, the power supply in the machine might possibly be faulty in its 5 V. voltage as supplied to the console... in which case, a constant monitoring of the 5 v. line with a meter or an oscilloscope might reveal whether the 5 V supplied fluctuates or esp. drops below 4.6 V. or so, around the time just before the console restarts.
That would settle the question of whether the console is defective or the power supply.
I can point you to exploded diagrams of the machine, if you need any aid on how to dismount the console. Or aid on where the power supply is in this machine, etc.
Or if this sounds too elaborate or to much effort, I can point you toward a good service company or three, servicing Health Rider equipment, might be located in your region.
Let me know. Thanks.