A burner having an elongate, generally tubular sheet metal body having an inlet end, a closed distal end and a tubular segment extending between the ends. The media player comprises a communications interface, a memory store containing a plurality of personalized advertisements, and a media playback component. The vaporizing section 22 comprises a vaporizing tube 20 having one end connected to a reaction tube of the MOCVD system and having the other end connected to the gas outlet 7 of the dispersing section 8, and heating means for heating the vaporizing tube 20. The method includes reading a predetermined number of spare blocks into the memory,and while reading a defect data block, checking whether a corresponding replacing spare block is stored in the memory.