Performance Tests and Calibration 6Keysight U1253B User’s and Service Guide 185Resetting the security code to factory defaultIf you have forgotten the correct security code, you may follow the steps below tochange the security code back to the factory default (1234).1 Record the last 4 digits of the instrument serial number.2 Turn the rotary switch to the position.3 Press and simultaneously to enter the Calibration Security Codeentry mode.4 The secondary display will indicate “CSC:I 5555” as a cue for you to enter thesecurity code. However, since you do not have the security code, proceed tothe next step.5 Without entering the security code, press for more than 1 second toenter Set Default Security Code mode. The secondary display will indicate“SCD:I 5555”.6 Press or to start and choose which digit to edit, and press or toedit the value. Set these to be the same as the last 4 digits of the instrumentserial number.7 Press (Save) to confirm the entry.8 If the number entered is the correct last 4 digits of the serial number, theupper left corner of the secondary display will momentarily show “PASS”.Now the security code has been reset to the factory default, 1234. If you wish tochange the security code, refer to the section “Changing Calibration SecurityCode” on page 183. Make sure you record the new security code.Please refer to Figure 6-6 on page 186.NOTE If you do not have a record (or have lost the record) or the security code, first trythe factory default code, 1234, through the front panel. There is always thepossibility that the security code has never been changed at all.
