Ceramic Terminal Strips
To remove a ceramic terminal strip, unsolder all com
ponents and connections, then pry the strip, with yokes
attached, out of the chassis. An alternative method is to
use diagonal cutters to cut off one side of each yoke (with
out damaging the spacer) to free the strip. After removing
the strip, the remainder of each yoke can be easily ex
tracted from the chassis with a pair of pliers. The yokes
need not be salvaged since new ones are furnished with
new strips. The spacers, however, may be reused.
To install a new strip, place the spacers in the chassis
holes, insert the yoke pins through the spacers, and press
down on top of the strip above the yokes. Use a plastic or
hard rubber mallet, if necessary, to seat the yokes firmly.
Be sure to tap above the yokes to keep from placing too
great a strain on the strip. Fig.
4-6
illustrates the way
parts fit together. If desired, the extending portion of the
yoke pins may be cut off to within ’/ 8 inch of the lower
end of the spacers.
C era m ic S trip
Y oke
Fig. 4 -6 . Installation of a ceramic terminal strip.
Observe the soldering precautions described previously
when soldering the leads to the strip.
OBTAINING REPLACEMENT PARTS
Standard Parts
Replacements for all parts used in the M Unit can be
purchased directly from Tektronix, at current prices. Many
of the components, however, are standard electronic parts
that can usually be obtained locally. Before purchasing a
part, be sure to consult the Parts List to determine the
tolerance and rating required. The Parts List gives the
values, tolerances, ratings and Tektronix part numbers for
all components used in the unit.
Special Parts
In addition to the standard electronic components men
tioned in the previous paragraph, special parts are also
used. These parts are manufactured or selected by Tek
tronix to satisfy particular requirements, or manufactured
especially for Tektronix by other companies. These parts
and most mechanical parts should be ordered directly from
Maintenance— Type M
Tektronix since they are normally difficult or impossible to
obtain from other sources. All parts can be obtained
through your local Tektronix Field Engineering Office.
TROUBLESHOOTING
General Information
This portion of the manual will aid you in troubleshooting
the M Unit in the event that trouble develops. When
troubleshooting, correlate the information in this section
with information in other sections of the manual.
No attempt is made to give a complete step-by-step pro
cedure for finding the cause of each possible type of
trouble. Instead, an attempt is made to outline a trouble
shooting guide. This guide provides a means for deter
mining the probable cause of a trouble from symptoms
observed.
A block diagram and complete schematic diagrams are
contained at the rear of this manual. Reference designation
of each component and voltages, waveforms, and test
points are shown on the schematic diagrams.
All wiring in the M Unit is color coded to simplify cir
cuit tracing.
Test Points
Certain major test points are shown on the circuit dia
grams and in Fig. 4-7. A test point is indicated by the
numbered circles with an arrow pointing to the location of
the test point in the circuit. Test points aid in trouble
shooting and calibrating the unit.
Waveforms and/or
voltages are shown at each test point on the circuit dia
grams. The conditions under which the waveforms and
voltages were obtained are also indicated on the diagrams.
Test points are numbered consecutively starting with
the diagram of the 4-Channel Switched Amplifier. Numbers
increase from left to right across the page and continue
from left to right across the Channel Switching Circuit
diagram. The numerical arrangement of the test points
should make it easy to find any particular test point.
Preliminary Troubleshooting
Before troubleshooting, check front-panel controls to
determine if the settings are proper for your particular ap
plication. If you are in doubt as to the proper settings of
the controls and their function, refer to the Operating In
structions section. If you determine that a trouble definitely
exists, proceed to isolate the trouble by making the fol
lowing preliminary checks:
1. Oscilloscope or M Unit
When following a troubleshooting procedure, it is assumed
that the oscilloscope used with the M Unit is operating
normally. This is not always the case. If in doubt, check
the operation of the oscilloscope before attempting to
troubleshoot the M Unit. Troubles occurring in the oscillo
scope can usually be detected by substituting another
plug-in unit for the M Unit (such as another M or CA Unit).
4-3
