HP 4328A Service Manual

Model 4328A
Section Vlll
Paragraphs 8-1 to 8-13
SECTION VIII
TROUBLESHOOTING AND CIRCUIT DIAGRAMS
8-1. INTRODUCTlON
8 -2.. This section contains troubleshooting instruc-
tions, schematics, and component locations [or the
milliohmmeter. Also included is an overall block
diagram that indicates the location of test point in the
instrument
8-3. Reference designations shown within circuit
card outlines are abbreviated, To find the part m the
Reference Designation Index, use the full reference
designation. For example, R305 on the A3 Oscillator
Assembly is listed as A3R305.
8-4. The Schematic Diagram Notes in Figure 8-1
pertam to all the schematics. Additional notes on the
schematics indicate test conditions, and special
information for use when maintain the instrument.
8-5 .. TROUBLESHOOTING
8-6.. Table 8-1 is the Overall Troubleshooting chart
for the milliohmmet~r. Procedures for isolating cir-
cuit malfunctwns to specific stages are based on the
use of the YEW Type 2782 Standard Resistors and
YEW Type 2786 or GR Model 1432T Decade Resistance
Box and the calibration procedures in Section V. The
mformation obtained when calibration is attempted is
used to troubleshoot the instrument.
8-7.. Table 8-1 contains references that dtrect the
user to the detailed troubleshooting charts, Table 8-2
through 8-10.. The detailed charts refer the user to
transistor stages.. [n a few instances, specific parts
are called out as being possible causes of circuit mal-
function, however, the troubleshooting charts are not
intended to locate specific parts that have failed.
They are intended to locate only malfunctioning stages.
8-8. SCHEMATICS
8-9 The schematics contain signal routmginforma-
hon, nominal voltage levels, and notes that assist in
understanding the circuit. They are laid out to show
electrical operation, and are not intended as wiring
diagrams.
8-lO. Component location photographs next to the
schematics indicate the physical location of parts.
Test pomts are also shown.
8-ll. Factory selected parts are indicated by an
asterisk. These are components that generally are
installed to fulfill circuit operatwn requirements ..
They may be the nominal value, or they may be some
value close to nominal. In any case, if the component
fails, ctrcuit operation should be verified after these
components are replaced ..
8-12. Component values are shown as follows unless
otherwise noted.. Resistance in ohms, capacitance
in microfarads and inductance in microhenries.
8-13. Wire color is indicated as WHT./ YEL i VIO.
First color identifies ground color, second color
identifies wide stripe, tlurd color identifies narrow
stripe.
8-1

HP 4328A Specifications

General

Brand	HP
Model	4328A
Category	Measuring Instruments
Language	English