A: No. "Wecker" is a colloquial term for the eccentric mechanism. The model number is the same. If you search for "Proxxon Wecker manual," you will end up at the LU-6868 page.
Dirty volume potentiometer or dead capacitors. proxxon lu-6868 wecker manual
It’s very possible the is either:
If you notice belt slippage or unusual noise, you may need to adjust the belt tension. Perform this procedure only when the drill is : and acoustic guidelines.
The manual clearly states:
A dedicated section outlining electrical safety protocols, ventilation constraints, and acoustic guidelines. proxxon lu-6868 wecker manual