Theory Of Operation; Troubleshooting; Recommended Test Equipment; Repair - HP 4262A Operating And Service Manual

Model 4262A
Section VIII
Paragraphs 8-1 to 8-10
SECTION VIl
SERVICE
8-1. INTRODUCTION.
8-2. This manual section provides the information
and instructions required for servicing the HP
Model 4262A LCR Meter. Included are Theory of
Operation and Troubleshooting Guide with Circuit
Schematics. The Theory of Operation describes
fundamental principles and circuit operating
theory of the 4262A with block diagrams. Circuit
schematics, locator illustrations, troubleshooting
guide, circuit analysis and other technical data ne-
cessary for repairs are integrated into the service
sheet foldouts. An illustration of the instrument
interior is shown in Figure 8-21,
Note
When the instrument circuitry in-
cludes expanded capabilities pro-
vided by optional equipment, refer
to paragraphs entitled OPTIONS
for specific option service informa-
tion.
WARNING
TROUBLESHOOTING AND RE-
PAIR ARE ALLOWED FOR
QUALIFIED TECHNICAL PER-
SONNEL ONLY. IF YOUR IN-
STRUMENT FAILS, REFER IN-
STRUMENT TO SERVICE PER-
SONNEL. H-P SERVICE OFFICES
OFFER YOU THE BEST ANSWER
TO YOUR PROBLEM. A GUIDE
TO YOUR LOCAL H-P SERVICE
OFFICES MAY BE FOUND ON
THE BACK COVER OF THIS
MANUAL.
8-3. THEORY OF OPERATION.
8-4. This theory of operation has been organized
into three sections: basic theory, a block diagram
discussion, and circuit analysis. The basic theory,
beginning with paragraph 8-11, explains the con-
cepts and fundamental theory of the 4262A in-
strument technique adapted for accurately meas-
uring the DUT and for fully achieving automated
measurement performance. The block diagram dis-
cussion describes the overall circuit operating
theory of the 4262A with block-to-block signal
flow. Included are block and timing diagrams. The
circuit analysis provides a detailed description of
how the circuit on each board functions. For
reference convenience, when servicing the instru-
ment, a circuit description is included in the service
sheets.
8-5. TROUBLESHOOTING.
" 86. This troubleshooting guide provides instruc-
tions and information for locating a faulty circuit
instrument component that requires service. All
instructions consider the safety of service person-
nel who will perform the procedures. These di-
agnostic guides are in the form of step-by-step pro-
cedures with flow diagrams. The board level
troubleshooting diagrams are the procedures for
isolating the problem to an individual malfunc-
tioning circuit board assembly. The guides for
locating a defective component are given on the
individual board service sheets and integrate service
support data: test point locations, waveform
illustrations, voltage data, timing digrams, and
other technical information in addition to provid-
ing schematic diagrams for each board. To facili-
tate easy troubleshooting of the 4262A digital
section, the troubleshooting guide for the logic cir-
cuit employs a signature analysis technique incor-
porating the concept of data stream analysis. A
guideline to signature analysis is provided in
Figure 8-12.
8-7. RECOMMENDED TEST EQUIPMENT.
8-8. The test equipment required to perform op-
erations outlined in this section is listed in Table
1-4 (Section I). The table includes: type of instru-
ment required, critical specifications, use, and re-
commended model. If the recommended model is
not available, equipment which meets or exceeds
critical specifications listed may be substituted.
8-9. REPAIR.
8-10. Repair explanations tell how to replace
defective circuit components. The recommended
replacement procedures for components and parts
which require special repair, replacement tools, or
test equipment should be observed. Correct dis-
assembly and the exchange procedures for such
special parts are outlined in Paragraphs 8-46
through 8-52. To prevent damage from improper
repair procedure, refer to the appropriate manual
section before proceeding with repair.
8-1