Parkside PWS 125 F5 angle grinder - starts as if the regulator was set to, for example, 3 when it is at 6. When cutting, it regains power but does not respond to potentiometer settings. I noticed that it is "sooted" in one place. Does such a regulator have a SOFT-start because I am thinking about bridging it (I will get rid of the speed regulation, which is unnecessary for me). What could possibly be damaged?