disc not spinning at all

I have inherited a sony ps3 model #cech-2501b. at first it would not accept a ps3 formatted disc. after removing the top cover I then removed the disc acceptor cover. I then proceeded to realign the plastic guide fingers. it then would accept said disc. however, the mechanism responsible for spinning the disc would not engage. the center drive and the magnetic disc holder works as designed. now it will spin but only intermittently.

I have had some experience with Japanese electronics not being properly solder in place. could this be a cause ?

sincerely pat at hartzelpb@live .com