Marks are to denominate the origin of goods.
Nintendo built Gameboys for decades.
Some GameBoys have aftermarket parts like the NAKI Action Light, a peripheral never made by Nintendo but was nothing but a light and a 1.5 magnification lens. It was advertised as "Fitting a Game Boy TM" and didn't use Nintendo marks. That is nominative use and allowed.
Then, Nintendo actually had stocks of spare parts that ended on the open market by now. those are genuine Nintendo parts, made for Nintendo, with the marks on it. Those are proper marks.
Some people bought up tons of old Game Boys and took them apart for spares. Those are still genuine parts, even if used, and the mark is proper.
Nintendo didn't make all the parts for Gameboy themselves. They had contracted OEMs (original equipment manufacturers) that created parts for construction of the toys. These were in part branded and marked in the OEM factory still, the OEMs had a license to make and mark parts. Parts produced till the lapse of the license would be most likely proper as for most intents and purposes Nintendo did endorse the manufacturing in this fashion. However after the licensee lapsed or if it doesn't contain a "put the markings on it" clause, marking would not be allowed (anymore).
Finally, there are spare parts that were just made to Nintendo specs, that are not originating with Nintendo, and are marked with Nintendo marks. Such copy parts infringe on the Trademark of Nintendo.
There is legal space in the aftermarket spare part market: Parts that are to specs but not marked with the marks denominating the origin. Those can be advertised akin to the NAKI Action Light "fitting a Game Boy TM" without infringing on marks.