Wii won't work after "incorrect memory card" was inserted.

Howdy,
So, my youngest inserted a disk, and then inserted what he thought was the memory card containing info for that game. He received an "incorrect memory card" error, so he tried another card, and another, and another (4 total tries), at which point, the lights flashed green, yellow, red, then powered down.
No, after unplugging the unit, and replugging, the power light comes on however, if you try ANYTHING else, (install a disk, press reset, press eject, etc.) the power light goes out and won't come back on till it's unplugged and replugged.
Nintendo wants $75.00 for a warranty repair...
I deal with computer/laptop hardware 70 hours a week. This has me stumped. So does the charge from the manufacturer. It's not been physically damaged, unless installing a memory card that has no information pertaining to the game does damage.
Any ideas would be greatly appreciated.
Thanks,
Harvester3