Ive been looking around used marked to find a r4 and ive found this r4. (https://i.ebayimg.com/00/s/MTYwMFgxMjAx/z/w~sAAOSwZqZaNaUd/$_59.JPG)
On some website (gbatemp, ) it clearly state that his cart is not supposed to be compatible with ntrboot, but on https://3ds.guide/ntrboot it say that...