got the game patching enabled, and I guessed I messed up the files then, also the ips version of the code.bin causes the power off errorFirst, do you have checked on Luma's config the option to load external code ?
if so and you've a black/grey screen when launching the games, it's that you messed up with the files, open pk3DS use the option to restore them
AND ONLY edit Wild Encounter / Trainer Datas. Don't go elsewhere. I did that first time (checked personnal files, and got it corrupted)