Secure
Power
Chapter 3 Calibration Procedures
Calibration Security Code
4Unsecure the power supply.
unsecured
The power supply is unsecured when you press the Secure key. You will see the above message from the front panel for one second. The "CAL MODE" message is displayed on the front panel after above message.
5Turn off the calibration mode.
Turn off the power supply to exit the calibration mode.
To
To Unsecure the Power Supply Without the Security Code
To unsecure the power supply without the correct security code (when you forget the security code), follow the steps below. See "Electrostatic Discharge (ESD) Precautions" in chapter 5 before beginning this procedure.
1Disconnect the power cord and all load connections from front terminals.
2Remove the instrument cover. Refer to the disassembly drawing on page 119.
3Connect the power cord and turn on the calibration mode by pressing the "Calibrate" key while simultaneously turning on the power supply then continue to hold the "Calibrate" key for about 5 seconds until a beep is heard. Be careful not to touch the power line connections.
4Apply a short between the two exposed metal pads on JP5 (located near U13). The JP5 is outlined with a circle on the component locator drawing on page 120.
5While maintaining the short, move to the security code and enter any unsecure code in the calibration mode. The power supply is now unsecured.
6Remove the short at JP5. (An error occurs if not removed.)
7Turn off and reassemble the power supply.
Now you can enter a new security code. Be sure you take note of the new security code.
60
