i wanted to desolder some parts from my upboard, but i cant get the solder to meld
. I used flux, Solder Iron (480 C) and a desolder Iron with Vacum sucker (480C), i pressed the Solder Iron againts the backside of the board and the Desolder Iron on the front but i cant get i to meld. Do you guys have any tip for me how to get the solder flow ?