WII black screen after power light is on but doesn't do anything. Have to unplug unit to power down. Could it be a bad blue tooth mod?
To clarify, your Wii doesn't cue the start-up screen and does not respond to input (like pressing POWER) after reaching this state. So that means it's probably freezing. Did you port over the data with the normal Wii data systems, or did you use an unlicensed program on your computer or Wii? It's very likely that any unauthorized programs might be too much for the console to handle, or might have viruses intended to freeze up your Wii. That goes for the Bluetooth program you mentioned as well.
The best thing you could do here is remove the SD card, and if you have a way to access the Wii through a computer, restore its basic factory programs and nothing more.
If you can't get to it through a computer, then remove anything connected to the Wii-USB plugins, discs, the SD card, even the batteries in your remote-and try starting it up again. Decreasing the input levels might free the way for the console to start. If you do get it up and running, power up one Wii Remote, and navigate through menus to delete your Wii data-there's a way to do that in Settings. Depending on where you are, you either want to wait for the menu to load, or click to the next option as quickly as possible. Some submenus load at the same time as their parent menu, so you want to get past the parent quickly before it tries to load too much data for your damaged OS to handle. On the flip side, other submenus load only when selected, and so you'd want to wait for the parent to load before clicking so as not to overload the system in that way. It's all guesswork there; without knowing the code, you can't tell which type of submenu it is.
If you can't get past the freezing black screen, call a professional source. Nintendo is the highest quality, but very expensive. I do believe Play-N-Trade does console repair/replacement; there might not be a location nearby, though.
Finally, try not to use unlicensed programs... unless lots people on the internet say the program works. (: