puzzu:
yes i applied +5vdc, and i checked with the oscilloscope it is +5 and -5
Are you using an ordinary hobby servo from an analog radio control system?
You don't need a scope, you need a DC voltmeter between the servo +ve and ground connections. This should read the same as the voltage the servo is designed to work with - typically 5V for an ordinary RC servo, but you haven't said what you're using. The servo ground needs to be connect to the Arduino ground, and the servo signal needs to be connected to the Arduino signal pin.
If you're using a different type of servo it may have different power and signal requirements,so you need to be clear about what sort of servo you're using.