This is an old thread, but I thought I would add...
On my differential diagnosis here the likelihood of a power flex tear would be pretty low.
If you were trying to burn out the backlight fuse to perform a teaching demonstration of how ipads lose their backlight----this would be exactly how you would do it. Pull the LCD flex while the iPad is not only on, but the LCD is lit.
Hopefully, the fuse isn't burned and the iPad just needs a hard reset (described above---power button plus home button together for 10 seconds).
If that doesn't solve it, then this is highly likely a backlight failure and you'd need to send it out for backlight repair.
Once you dry fit the components, plug in the dock connector to prompt it to boot--if backlight is okay, then iPad will show a display. If not, then confirm backlight failure by plugging into iTunes---if iTunes sees the device, but the device has no display = backlight.