hey, that is kind of strange that they stopped suddenly, also your syscheck does look ok
you might want to try a different loader then, are you talking about cfg usbloader or gx?
Guide: Installing CFG Loader
or wiiflow (linked below)
in general i would go for
videomode: console default or directly force it to pal
and boot standard ios: to 250 (if possible in your loader, when not 249) and only change it to 223 or 222 when needed, like metroid or guitar hero stuff.
are you disc loading, you might only have a dirty lens which causes problems, there are discdrive cleaning kits available, a strong blow in the drive slot might also help..
ah now i get it, so there are still running games of your collection?