I am going to guess that you where using an older v1 beta of usbloader gx which has been know to brick wiis from time to time in the manner you have described. If priiloader/preloader is not working there is very little you can do. You could pursue the possibily of a hardware brick, but I doubt that is your issue.
Step 1- get a gc controller an do savemiifrii, see if the recovery menu loads when you do savemiifrii.
Step 2- test your wiimote by powering on the wii with a synced wiimote. Does the wiimote power the wii on or not.
If the wiimote does not power on the wii and savemiifrii does load the recovery menu, likely your bluetooth module is not working. However, priiloader/preloader would still work in this case, perhaps you don't have preloader installed, or bt module is not your issue.
If the wiimote does power on the wii and savemiifrii does not load the recovery menu, consider-
Full brick from bad homebrew misshape, or
Bad Wifi module- to test wifi, replace with a known working module. The menu would then load, if not then the wifi is not the issue.
Very bad disc drive- Very rare, to test remove your wii dvd drive, the system menu should load without the dvd drive, if not then the dvd drive is not the issue.
Assuming that your hardware is fine, you likely have a fully brick. In this case contact deadlyfoez, streamline hd, or krafter to have your nand reprogrammed using the nand backup you made during the softmod process.