This wii was originally Korean then (poorly) region changed, then bricked by an official update to 4.3.
This can be remedied by either uninstalling the Korean key from the seeprom using Korean Kii, or by installing an unstubbed ios60 to ios slot 80, or by properly downgrading to 4.1 or lower
The tricky part is getting back into a homebrew environment to do one or more of those things.
You can try the bluebomb exploit, or the savemiifrii method + an exploit to launch homebrew, but in this area all I am able to do is point you in the right direction and where to start looking.
Oh, it's probably unlikely but save a working bootmii folder to your sd card and boot up the wii with it inserted. If you are lucky enough to have bootmii installed to boot2 it will load and solving this problem will be a piece of cake. Here's a link to the bootmii folder http://static.hackmii.com/bootmii_sd_files.zip
Yes, this is what I said above. 003 bricks only occur in Wii's that were originally Korean then poorly region changed
(That being said, while rare its also technically possible to get this error on a non-Korean console if on 4.2 and 4.3 with a stock IOS70 or IOS80 IF someone were to add the Korean key to the seeprom using the KoreanKii app, but this is very unlikely to happen, you would almost need to go out of your way to intentionally 003 brick yourself on a console that wasn't originally Korean and region changed)
If the console was region changed, it is not stock and was once upon a time softmodded. Visible traces of the mod may have been removed, but hopefully you still have bootmii installed to boot2 (if it was ever installed). You would have no way of detecting this short of doing what I advised above.