Why does solder no longer have lead in it?

Since question is not clear two answers can be given on the assumption that the question is about dry soldering. Thoroughly clean the part to be soldered, apply flux re-solder the connection.

The second answer is normally lead will not be kept on a soldering point. the technician doing soldering has to use lead and flux separately.

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There are still solders that contain lead. The European Union prohibited excessive amounts of lead in consumer products (WEEE and RoHS), so there are lead-free solders. But there are industries in which the lead-free solders are not acceptable.