Troubleshooting; Introduction; Troubleshooting Aids - Tektronix 2205 Service Manual

INTRODUCTION

Preventive maintenance performed on a regular
basis should reveal most potential problems before
an instrument malfunctions.
troubleshooting be required, the following infor­
mation is provided to facilitate location of a fault. In
addition, the material presented In the Theory of
Operation and Diagrams sections of this manual may
be helpful while troubleshooting.

TROUBLESHOOTING AIDS

Schematic Diagrams
Complete schematic diagrams are located on
tabbed foldout pages in the Diagrams section.
Portions of circuitry mounted on each circuit board
are enclosed by heavy black lines. The assembly
number and name of the circuit are shown near
either the top or the bottom edge of the enclosed
area. ::
Functional blocks on schematic diagrams are
outlined with a wide grey tine. Components within
the outlined area perform the function designated by
the block label. The Theory of Operation uses these
functional block names when describing circuit
operation as an aid in cross-referencing between
the theory and the schematic diagrams.
Component numbers and electrical values of
components in this instrument are shown on the
schematic diagrams. Refer to the first page of the
Diagrams section for the reference designators and
symbols used to identify components. Important
voltages and waveform reference numbers (en­
closed in hexagonal-shaped boxes) are also shown
on each diagram. Waveform Mustrations are located
adjacent to their respective schematic diagram.
Circuit Board Illustrations
Circuit board illustrations showing the physical
location of each component are provided for use in
conjunction with each schematic diagram. Each cir­
cuit board illustration is found in the Diagrams sec­
tion on the back of a foldout page, preceding the
first schematic diagram (s) to which it relates.

TROUBLESHOOTING

on the circuit board illustrations with hexagonal
outlined numbers corresponding to the waveform
numbers on both the schematic diagram and the
waveform illustrations.
However, should
tration of the bottom side of the Main circuit board.
This illustration aids in troubleshooting by showing
the connection pads for the components mounted
on the top side of the circuit board. By using this
illustration, circuit tracing and probing for voltages
and signals that are inaccessible from the top side of
the circuit board may be achieved without dis­
mantling portions of the instrument.
Circuit Board Locations
ment is shown in circuit board locator illustrations.
These illustrations are located on foldout pages
along with the circuit board illustration.
Circuit Board Interconnections
provided as an aid in tracing a signal path between
circuit boards. All wire, plug, and jack numbers are
shown along with their associated wire or pin
numbers.
Power Distribution
in troubleshooting power-supply problems. This dia­
gram shows the service jum per connections used to
apply power to the various circuit boards. Excessive
loading on a power supply by a circuit board fault
may be isolated by disconnecting the appropriate
service jumpers.
Grid Coordinate System
tration has a grid border along its left and top edges.
A table located adjacent to each diagram lists the
grid coordinates of each component shown on that
diagram. To aid in physically locating components
on the circuit board, this table also lists the grid
coordinates of each component on the circuit board
illustration.
Maintenance—2205 Service
The locations of waveform test points are marked
Also provided in the Diagrams section is an illus­
The placement of each circuit board in the instru­
Circuit Board Interconnections (Diagram 9) is
Power Distribution (Diagram 8) is provided to aid
Each schematic diagram and circuit board illus­