A method is provided for determining a shorted thyristor cell in a bridge that supplies a load from a source, the bridge including a plurality of the thyristor cells. The controller activates and deactivates each switch assembly one time during each switching cycle and activates one subset of switch assemblies before activating the remaining switch assemblies. Furthermore, the invention specifies a method for producing a light-emitting diode module and an optical projection apparatus having such a light-emitting diode module. The light housing and at least one light source is mounted to a printed circuit board, which is supported underneath the light guide by a vehicle structure. Also provided are a method for use in a print system and one or more computer readable storage media having computer-executable instructions for use in a print system which allow parameters to be changed for an image to be reprinted. The plasma processing apparatus includes: at least one arm; and a supporting portion extending from the arm toward a substrate seating position of the substrate, so that the plasma processing apparatus can reduce the likelihood of arc discharges compared with conventional dry etching to increase process yield and product reliability, and ensure stable mounting of a substrate.