Recently I met some TSDZ2 issues.
This video is about the latest and a little more help for diagnosing.



The walk assist mode is important for diagnosing. If it is not enabled yet we have to enter to the hidden menu on display. At VLCD5 display press the "i" and "power on" buttons simultaneously for 3 seconds on the startup screen, then quick press the "i" button 4 times for hidden settings. At XH18 display press the "i" and "power on" buttons simultaneously for hidden menu. If the mode enabled we can switch on the motor with long pressing the "down" button.
For plastic gears use silicone based grease, because oil based grease can change the properties of the plastic.