mhzs cd88e request for help from Italy

Hello, I am ever in trouble.
About two years I had my player stopped because the laser does not read the disc. I had already changed the laser, replacing the original Sony KSS 213q with a 213c , but without result.
Now a friend of mine who works as technician in a television has tried to repair it. I bought a new optical  original Sony(KSS 213q), but despite his efforts the player does not want to read cds. The pick up is ok, the disc turns, first slow and then quickly, the fire below the surface of the disk if this dance (and so is ok), but it does not read the directory, and then he says NO DISK. Without schematics my friend does not do anything more (he even tried to contact Sony support, but they do not get their hands on MHZS). Do you have any suggestions or is it just time to throw it away?
Thanks and regards
Alessandro

Hello kk_ho,
yes, my friend has de-soldered the new laser ( otherwise laser should be dead, instead of moving trying focus... )
Many thanks
Alessandro