Troubleshooting; Troubleshooting Aids - Tektronix 7B92A Maintenance Manual

The following information is provided to help troubleshoot this instrument. Information contained in
other sections of this manual should be used along with the following information to aid in locating the
defective component.
particularly where integrated circuits are used.

TROUBLESHOOTING AIDS

Diagrams
Circuit diagrams are given on fold out pages in
Section 8. The component number and electrical value
of each component in this instrument is shown on the
diagrams.
Components that are mounted on circuit boards
are outlined on the diagrams with a heavy black line.
Voltages and Waveforms
Typical operating voltages are shown on the
diagrams. Voltage Conditions given on the diagram
page indicate the test equipment used and the front-
panel control status necessary to obtain the given
voltages.
Typical operating waveforms are shown next to
the diagram where they were measured.
waveform is numbered to locate the point on the diagram
where the waveform was taken. Waveform Conditions
given on the diagram page list the test equipment used
and the front panel control status necessary to obtain the
given waveform.
Circuit Board Illustrations
Circuit board illustrations are shown on the fold
out page preceding the associated diagram. Each board
mounted electrical component is identified by its circuit
number, as are interconnecting wires and connectors.
Figure 8-1, in the front of the diagrams section,
shows the location and assembly number of each circuit
board in this instrument.
Switch Cam Identification
Switch cam numbers shown on diagrams
indicate the position of each cam in the complete switch
assembly. The switch cams are numbered from front to
rear.

TROUBLESHOOTING

An understanding of the circuit operation is very helpful in locating troubles,
Each
Diode Color Code
The cathode end of each glass-encased diode is
indicated by a stripe, a series of stripes, or a dot. The
cathode and anode ends of metal-encased diodes are
identified by the diode symbol marked on the case. For
most silicon or germanium diodes with a series of
stripes, the color code identifies the four significant digits
of the JEDEC or vendor number using the resistor color-
code system.
Wiring Color Code
Insulated wire and cable used in this instrument
is color-coded to facilitate circuit tracing.
Semiconductor Basing
Figure 4-2 illustrates the basing configurations
for all semiconductors used in this instrument. Some
plastic case transistors have lead configurations that do
not agree with those shown here.
transistor is made by a different manufacturer than the
original, check the manufacturer's basing diagram. All
transistor sockets in this instrument are wired for the
standard basing used for metal-case transistors.
Inter-Board Pin Connector Identification
The inter-board pin connector sockets are
installed on circuit boards in groups of 5 sockets (as in
Fig. 4-3). Socket number 1 is indexed on the circuit
board with either a triangular mark or the number 1.
Each group of sockets is identified by its J (jack) number
etched on the circuit board. The J numbers correlate to
the J (jack) and P (plug) circuit numbers on the
schematic diagrams.
4-3
Maintenance-7B92A
If a replacement