Hi @pi123
had you tried testing with other CDs?
If so and it is not working well, most probably the lens mechanism is faulty.
If it is under warranty, send in for service.
Else consider getting a quote on the the cd traverse mechanism / lens.
im not sure about this model, but if you want to DIY to fix it, consider opening up to the lens / traverse mechanism
hopefully there are part numbers which you can try searching in ebay / aliexpress, etc