Keysight U3606B, Service Manual

Page: 69 / 123

Calibration Procedures 1
Keysight U3606B Service Guide 69
Resetting the security code to the factory default
If you have forgotten the correct security code, you may follow the steps below to
change the security code back to the factory default (ATU3606B).
To unsecure the instrument without the correct security code, follow the steps
below.
1 Disconnect the power cord and all input connections.
2 Disassemble the instrument using the “General disassembly” on page 113.
3 Solder a temporary short between the two exposed metal pads on the main
printed circuit (PC) board assembly. The general location is shown in
Figure 1-18 . On the U3606B PC board, the pads are marked as “SECUR”.
NOTE
If you do not have a record (or have lost the record) or the security code, first try
the factory default code — “3606”, from the front panel or “ATU3606B”, from the
remote interface — before you use the procedure below.
WARNING
Be careful not to touch the power line connections or high voltages on the
power input module and transformer. Power is present even if the
instrument is turned off when the line cord is connected.