Assume it is provided with suitable raw input materials. It can't receive any outside assistance apart from being provided the input materials in a way that doesn't take over parts of the production process. No fabricating individual components that are to be assembled by a different system, it must fully reproduce itself in a way that looks like converting raw input materials into copies of itself fairly automatically, such that those copies could go on to produce a further copy if provided inputs in the same fashion.

If it's a two stage process, where a system produces something else that can then produce it, and then that thing fabricates a copy of it only provided input materials, that counts.

An Earth-originating AI that technically has such a 3D printer, even if humanity can't access it, counts.