SDM stopped working, online instructions helped me to fix it

Just to share that, even if I am almost unable to work with small parts (really), these instructions were easy enough to make me try:

http://bangmedia.no/pentax/sdmfix/

and, although probably I didn't make a perfect job (I am not sure if the motor screw is too tight now), the SDM of my 17-70 now works again!

it's a little bit louder than before (it sounds like a not oiled hinge), but it works at least

Or alternatively
https://www.pentaxuser.com/forum/topic/da--16-50-sdm-failure-55356

thanks, I'll keep that in mind