this section is contained in both the buffer (All)
assembly performs a number of separate func-
and active filter (A10) assemblies. Test point
tions, they are divided into the independent
a trouble exists in the analog section, proceed as
troubleshooting. Troubleshooting of the digital
section is performed in the sequence shown in
(1) Connect a battery powered differential
voltmeter to A10TP4 () and TP3 (+).
(2) Select the 10 volt range and VDC function
with each waveform is the applicable test point
(3) Turn on the voltmeter and then apply a
and timing relation to other waveforms. All
+10V DC input to its INPUT terminals.
(4) Verify that the differential voltmeter
in the continuous measurement mode.
indicates -10V DC is present at A10TP4 and
The storage cycle can be by passed if there
( 5 ) Apply full-scale input voltages on
is a suspicion that it is faulty (usually
selected ranges of 1,100, and 1,000 volts. Each
indicated by flashing digits) by jump-
range shall produce the same voltage specified in
ering A1TP5 (+5V) to A14TP2. If the
readout is then observed to be correct, the
For inputs of less than full-scale on any
the trouble lies elsewhere.
range, the voltmeter will produce a
proportionally less voltage at A10TP4
and TP3. For example, a +10V DC input
in the 100-volt range will produce -1V
(6) If the voltage at A10TP4, and TP3 is not
correct, the trouble is in the analog section which
consists of the buffer and active filter assemblies.
Applicable troubleshooting procedures for each of
If the voltage at A10TP4 and TP3 is correct, the
Troubleshooting procedures for the digital section
are contained in d below.
Remove t h e ratio input (A3) when
troubleshooting the digital section.
d. Digital Section.
The digital section circuitry