@Thomas > I understand your frustration, but please be aware that the cost of a new unit is almost always less than the "sum of the parts" if you were to buy them all as replacement components, especially considering the majority of said parts are produced to be installed in new products, not to have sitting around at repair centres as spares. Realistically, yes, a small electronics component could be repaired if that were indeed the fault, and I would side with you in that being the more cost effective approach to repairing it ... if that were the only fault and it were 100% that component at fault and it were deemed feasible to replace that component ... which, again, chances are they don't have just sitting around at repair centres as spares.
Then again, I don't operate or manage the repair centre for an international electronics company, and I don't believe you do either?
So I apologize that this is the result, and not necessarily a desirable one meeting your expectations, but unfortunately nobody here is authorized to provide you with technical instruction or direction on disassembly, repair, or modification of your Pioneer DJ product and, of course, my standard response at this point is to direct you to technical support.
If you are so inclined to repair it yourself, you are certainly welcome to do so and I hope you're able to get it repaired and working properly.