Are you sure you did not do something else? Sticking a thumb drive in your wii should not brick it, or do anything to it for that matter. You have taken it out and tried to turn on the wii, yes? So far it sounds like a no good situation. Did you install preloader?
If you did hold reset and power on the wii.
If you have a game cube controller you can try savemiifrii.
When you power the wii is it sending a black signal to the tv, or no tv signal at all. What about the wiimotes, can you turn the wii on with them, do they sync? How soon after you disabled your chip did this happen?