This manual applies to all instruments having serial prefix
1209U. Instruments with a serial prefix above 1209U may
have a Manual Change Sheet, to which reference should be made.
Section I contains General Servicing Instructions and a Description of Controls
Section II gives information on Parts Identification, Maintenance and Repair
Section III contains a list of Replaceable Parts for the 3720A.
Section IV gives the 3721A/3720A System Troubleshooting Procedure.
Section V contains the Functional Diagram, Assembly Location Diagrams and
Assembly Packages including Schematic and Component Location.