The solution is to suck the solder away with a tin absorber and weld it again.
The solution is as follows:
1, there is a soldering iron to suck. 1
2, sometimes the soldering iron oxidation does not account for tin, and then put some solder wire up, use the rosin inside to infiltrate the soldering iron head, a drag down.
3, this still depends on the feel. Basically I now use the solder wire directly for the patch device.
The computer motherboard and the chip are the ones that aren't welded together.
It doesn't have to be welded together. They burn easily, or they don't work.