I have a preloader installed, I installed system menu 3.2u. after installation I reset it in the wii options and my homebrew channel got deleted, system menu still works fine. Then I push the reset button while the wii is booting then I got a blackscreen every time I turn on the wii... I guess the system menu 3.2u overwritten preloader after...
Sure, test Savemiifrii, SaveMii Dongle or bootmii if you had it installed. BUT be sure that it's a black screen and NOT a blank screen becuase if it's a blank screen and the TV does barely react I guess you're wii can't be restored unless you've got a nand flasher. :)
Btw do you have a modchip installed, if you have you gain another option which is to use an autoboot disc to boot immadietly to disc channel. However none of this is possible if it's a blank screen brick. I know this becuase I've got a wii with blank screen brick.