when it was powered on did u hear the disc mechanism moving sound (sort of like a warm up procedure to get the disc drive ready) ?

is the Power button light green or red or orange after u press On ?
if you were using a power step-down adapter before this ... did u "forget" to use it this time ?

assuming you are not running modded Wii i guess this is the only things left to check before contemplating wii hardware repairs :-

1.  see if you can still SYNC the 1st player wiimote with the console.  Press SYNC red button on Wii SD slot and red button inside the battery area of wiimote.

2.  get another AV cable to test.... hopefully it's just cable problem

3.  check AV input on your TV is working with other devices or not

4.  check if you set Wii settings to display EDTV (480p) but your TV can't support or you are somehow not using a Component cable now

based on the fact that it is softmodded ... then there's a multitude of other possibilities.

eg.  system files related to booting up the machine got issue or unable to load System Menu ...

can't really help much if it's that then you'd have to search somewhere else i guess.
just out of curiousity, what was the last game you played bfor this issue cropped up?

Suspecting power brick problem.

If the game shop nearby, try power up ur Wii using their powerbrick + a/v cable