Check the carbon brushes. On older PST models, the brushes eventually wear down to the wire. If the motor sparks excessively or smells like ozone, it's time to replace the brushes. Maintenance Tips for Longevity
Loosen the two screws on the underside of the metal footplate. Bosch Pst 52a Manual Fixed
Seat the back of the blade into the groove of the guide roller. Tighten the screw firmly. Adjusting the Footplate For bevel cuts (up to 45 degrees): Check the carbon brushes
The PST 52A uses a manual screw-clamp system rather than the modern SDS "click" system. before touching the blade area. Bosch Pst 52a Manual Fixed