Reflowing cracked joints just like that? Yea, depending on your luck, you might get some life to the gizmo for a while. Expected lifetime? Days, weeks, months, possibly years if you're lucky indeed. For anything important/critical/worth your money, such is just a bad bad way to "repair" stuff. The joints probably failed due to bad intermetallic compound formation in the first place, just melting the same poop again won't do miracles.
This post was not written by a chemist nor a metallurgist, so take it with a grain of salt.