Repair guidance needed for ailing Rega Planet

A good friend has an original Rega Planet. When a disc is loaded into the player it produces a static or zapping sound out of the speakers. When skipping tracks or stopping play, the same sound can be heard. When you skip tracks it starts about two seconds into the track about 75% of the time. Rega did not seem to have a solution and suggested that it was probably the transport, which they did not have a replacement for. The transport is a Sony part, marked 1-645-722-51. Any guidance on the problem or leads on a spare transport would be greatly, greatly appreciated.
Marty