If you can operate the handbrake manually from the dash handle, the motor is working.
What seems to be the issue is that the unit has lost or forgotten it's limits.
Quite possibly cos of the new cables, discs, pads.
I had very similar issues before Christmas.
Find a local garage with a Renault Can Clip diagnostic system and ask them to reset the unit.
My local guy couldn't access mine with his renault system but did manage a fault reset with another diagnostic system.
This at least allowed me to take the thing for a drive, manually using the handbrake at every opportunity and gave it a chance to "re-learn"
Working sweet as a cherry now.
Basically, th reset tells the unit that parameters have changed and cycles it through to establish new limits...similar to setting up a new unit.
REnault main dealers can do the same thing but their default, at least the two near me, seems to be to replace the motor..which is crazy unless the thing is actually defective.
The grinding sound BTW is an internal torque limiter, similar to on electric drill/drivers.... but it does sound as though summat awful is happening so scares the pants off of people