- Are there solder paste over the stencil surface?
- Is squeegee torn down?
- Is there a void between stencil and the PCB?
- Is squeegee edge damaged?
- Is squeege pressure too low? (for 100 mm squuegee width, less than 1 kg)
- Are PCB supports weak?
- Is stencil damaged?
- Are there any solder paste, mark ink or similar material left around the area?