In article ,
"Arfa Daily" wrote:

First check that the sled movement is absolutely free - that there is no no
grease on the slides that has gone 'sticky'.

Could also be a gear with a missing tooth - I had a Sony Discman which
had that problem, about 20 minutes into a disc it would get stuck at one
spot and just keep repeating. The missing gear tooth was on the drive
which moved the optical pickup from the centre to the edge during play.