I'm having the same problem. I just bought this wii on last Sunday.
wii 3.4u, serial: LU6!!!!!!!!!!!!!!!!!!!
WadManager 1.3 won't load.
Custom WadManager loads.
Installed IOS16, and IOS249.
IOS Downgrader gives BLACK SCREEN OF DEATH
It was bought at Best Buy. I'm planning on returning it...