I'm new here, but I think I bricked my wii (4.2u). I tried installing the Blue Wii theme and it was installed fine, but when I restarted my wii it said,
"The system files are corrupted. Please refer to the Wii Operations Manual for help troubleshooting."
By the way, I DON'T have bootmii installed as a preloader.
I do have a NAND backup.
I think I have a banner brick.