1. Power down. Unplug ALL USB connections and let's extend this to all but the power connection. Try again.

2. If item 1 fails, power down, remove the charger, the battery then press and hold the power button for 60 seconds. Release, slip in the battery, apply power and test.

If this doesn't bring the machine up to the point the Asus splash screen doesn't show then it's a failed laptop and needs repair.