If it's installed correctly you should get a matrix splash screen when you turn it on and when you boot a game there will be a little infinity 1.X under the playstation 2 writing (I think modbo shows 1.99).
Although really you should just test it fully after you are done and before you put it fully back together. As it's possible to get the splash screen, but not have games boot (bios wires soldered correctly, dvd controller points not or wires too long). Auto switching of modes can also be a bit inconsistent if the reset wire is too long.
So best to just check everything before putting back together,rather than just assuming because you see the splash, it's fine.