youtube 改雷射筆

almost video are fake!!

to turn the screw is to concrol the output power of the IC,
the screw actting a controller of current flows to the IC.
be look CAREFULLY,
in your link
2:54 of the video,
he touch the metal part of the soldering iron,
its said that he haven't switch on the soldering iron,
may be he heat the IC,
but if you don't know,I perfer you do not try,
i don't want you to waste the laser.