Ps3 will not inject disc after laser replacement

I have installed a new laser in my Playstation 3 following a guide I found on this website. I was very careful to not damage anything and do everything in order. After the laser installation and reassembly, when inserting a disc, it will take it in, but not drop the magnet on the spinner. Therefore, the playstation does not register the disc. To get the disc back out, I have to bump the inserted disc with another disc while the machine is ejecting, and it will eject.