The older Prima's used the Philips Short Loader mechanism.
Due to a lot of issues, Philips promptly discontinued this drive and left a number of manufacturers out in the cold.
It is possible to get laser replacements, but the problem is typically in the servo board mounted under the drive.
I have 2 prima's and a Synthesis player that are scrap due to not being able to get servo boards.
Contact Globe Audio for the latest updates as to repairing these units.