Solved: how to hard reset i-Mate SP3 : Power off phone. Press both LEFT and RIGHT SOFT keys, then...

i-Mate SP3 hard reset with keys

Power off phone. Press both LEFT and RIGHT SOFT keys, then press POWER for a few sec. Keep holding these 3 buttons until you see

"Press 0 to restore factory default, other keys to Quit."

Press 0 to hard reset i-Mate SP3.