Model 166D, MX-2962/USM-i05A Section V
Paragraphs 5-1 to 5-5
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SECTION V
TROUBLESHOOTING
5 -1. IN T R 0 DU CT IO N .
TRIGGER SWEEP DELAYED -
- - TRIGGER
The procedure for troubleshooting the Model 166D ClRCU.lTS GENERATOR GENERATOR
is divided into two categories: (1) overall or system
I, troubleshooting and (2) sectional troubleshooting. RO
i For the purpose of system troubleshooting, the Model
166D is considered to be a system; the oscilloscope
is not included. The Model 166D is divided into the Figure 5-1. Functional Block Diagram
three sections shown in figure 5-1. System trouble-
shooting procedurb isolate troubles to one of the
sections, and sectional troubleshooting procedures
isolate troubles within the sections. 6-6 lists the adjustment required following replace-
ment of tubes, transistors, and diodes. If the trouble
5-2. TEST EQUIPMENT, in the faulty section is not obvious, proceed to the
appropriate sectional troubleshooting table.
The voltmeter-ohmmeter indicated in table 5-1 is
the only external test equipment required for trouble-
shooting the Model 166D. The oscilloscope in which 5-4. SECTIONAL TROUBLESHOOTING. '
the Model 166D is installed can be used to obtain
w-veforms where called for. Tables 5-3, 5-4, and 5-5 provide procedures for
sectional troubleshooting. The test points called out
5-3. SYSTEM TROUBLESHOOTING. in the tables are located in figure 5-2 and are shown
on the schematic diagrams, figures 6-2 and 6-3.
Before starting the system troubleshooting, visually Voltage and resistance diagrams are given in figures
check the Model 166D for such items as loose or broken 5-6 and 5-7.
parts, cold solder joints, etc. Following the visual
inspection, proceed to the system troubleshooting 5-5. LOCATION OF PARTS.
procedure given in table 5-2. When a faulty section
is located, check the section for obvious troubles. Figures 5-3, 5-4, and 5-5 show locations of assem-
In many cases instrument failure is due toa defective blies and components not called out in the instrument
electron tube. The instrument can then be returned itself. These assemblies and components are called
to service by replacing the tube and checking the out by reference designation and cross-referenced
calibration of the particular circuit repaired. Table in table 7-1.
Table 5-1. Test Equipment for Troubleshooting
Recommended
lnst&ment Type Required Characteristics Use
Instrument
DC Voltmeter/ Voltage Range: 1 volt to 400 volts Voltage and resistance mea- ME-25A/U
Ohmmeter surements or .
Accuracy: 3% @ 410B
or
Input Resistance: 100 megohms @ 4.12A
I,
Resistance Range: 10 ohms to
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10 megohms
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