Comentário oficial
I'm sorry, we don't have any manufacturing or engineering information available for you regarding any changes made to the SX2 production. They may have made modifications during the run simply due to changes in hardware availability, as is often the case (a perfect example is the change in the original CDJ-2000 model LCD provider). There was never any recall or service bulletin issued for the SX2.
Please contact a Pioneer DJ authorized service centre in your region to have your hardware inspected and/or repaired as nobody here is authorized to provide you with any information regarding disassembly, modification, or repair of your controller.