Hello, i built the 6582.. i finished everything and i'm so happy, but what break my happiness is the fact that 2 leds of the matrix can't turn on.. the strange thing is that they are inside the matrix (6 col, 3 row and 4 col 6 row), and the fact that another led had the same problem.. i added some iron and now it works.. i cant fix the other 2 whit the same method, they have enought iron now on each side. I've tested the joining and they are ok.. what could be the problem? thx ps. the leds works, putting 5 volt (whit the resistor) it light up pps.. is normal that all over the board some led are lightly lighted?