Generally speaking, there are three ways for us to idenfitfy the cold solder joint, such as:

1)Checking the solder joint directly. That’s to say, if the component is a cold solder joint, the solder edge and the welding surface won’t be matched in a good way;

2)Adding some external force to the welded component by hand, then pull ing and shaking a few times; If the component is no loosening, you can confirm that there is no cold solder joint;

3)The Functional Test is helpful for us to judge if the cold solder joint is or not.