Fluke 341A Instruction Manual page 35

FAULT ANALYSIS
If
there are
errors in test
point
resistance read-
ings,
check
the following
components.
TEST POINT
SENSE
Defective diode
CM
7
Defective
transistor
Q6
t
Oil
Defective
transistor Q9,
Q1I,
or
Q18
Defective diode
CRi,
CR2, CRB,
CR4
or
CR5
Defective diode
CR26
or
CR27
Defective
lamp DS5,
DS6
or
DS7
Defective capacitor
€54
Shorted
relay
K2A
and
K3A
Resistor
R369
changed
value
4-41.
STANDBY
TEST
4-42. This
test
determines instrument
power consump-
tion
and
verifies
proper operation of
the controlled current
Limiter
under standby
conditions,
a.
Set
Model
341
A/343A
controls as follows:
FUNCTION
OFF
4-43.
AUXILIARY SUPPLY
VOLTAGES
In the following
test,
the auxiliary supplies are
by measuring
their respective
output
voltages.
FUNCTION
RANGE
Voltage
Dials
341A/343A
controls
as follows:
STANDBY/RESET
10.00000 (Model 341 A)
10.000000 (Model 343A)
CURRENT
LIMIT
Fully clockwise
Connect
the
895A
common
to the
+
SENSE
terminal,
and
measure the following
test
point
voltages.
Vol-
tages
should be
as indicated.
TEST POINT
PC VOLTS
21 to
24
14.999
to 15.001
-14.5
to
-15.5
540
to
600
690
to
760
FAULT ANALYSIS
If
the auxiliary
supply voltages are not
correct,
check
for possible defective
components
as
follows:
RANGE
TEST POINT POSSIBLE
TROUBLE
Voltage
dials
10.00000 (Model 341 A)
10.000000 (Model 343A)
CURRENT
LIMIT
Fully clockwise
Connect the instrument
through
the
wattmeter
to a
1
15 volt
±1%,
60
Hz
source.
Set
FUNCTION
switch to
STANDBY/RESET. The
wattmeter
should indicate
approximately 10 watts
and
the
LIMIT
ON
lamp should
illuminate,
FAULT ANALYSIS
,
(1)
If
the
LIMIT
ON
lamp
STANDBY,
check
the
folic
for continuity,
test
point
2
proper
+15
and
—IS
volt
proper operation,
and contro
Defective
diode
CR19,
CR20
Defective transistor
Q23
or
Q24
Defective
transistor
Q19,
Q20
or
Q14
Defective
+15
volt supply
Defective
transistor
Q21
or
Q22
Defective
diode
CR2
Defective diode
CRI
CR2,
CR4
or
CR5
Defective diode
CR3