When the board is soldered, the pad is mostly off because the soldering time is too long or the soldering is repeated, causing the temperature to be too high. The pad copper sheet will repeatedly swell and fall off. When soldering, pay more attention to this to prevent more falling off.
The board cuts off the pad with a knife and cuts it to the non-shedding part to prevent the circuit from expanding along the falling point. If your component leads are long enough, you can scrape off the insulating paint at the cut-off circuit connector. Solder solders the far-sighted pins here. If your component leads are not long enough, you can use a thin wire with good solder to pass through the pad hole and solder to the component leads, and the other end to the pad connector. And use hot melt adhesive to prevent re-opening and falling off
If your pad is out of the way, it is very bad. For the above method, you can also choose the method of flying the wire, solder one end of the wire to the component of the desoldered component, and the other end is soldered to any solder connected to the soldered pad. Point. There is also a way to bridge, if there is a component on the same line around the soldered pad component pin, you can directly solder the component pin to the pin of that component, discarding the original pad, of course, When welding, it must be seen that the welding string cannot be welded to prevent burnt components.