... temperature range !solder and desolder ,suit for large area PCB BGA chip and Expansion slot of computer mainboard . MODEL ... temperature range is 100°C-500°C.if for PCB preheating ,suggest to set it about 300°C.it ... reach the one you set .4.adjust the PCB holder to match PCB ,make it fixed at the clip slot . ... it must tin-plate Chip pin pad or pin of PCB ,and put some solder flux .it can increase the ...