Fluke 410B - Page 22

4 10B
SYMPTOM
PROBABLE
CAUSE
REMEDY
1
No
output
r
c
lown
fuse
pen
heater
of V202
;heck
fuse
Fl,
and
replace
if
necessary.
Determine
if
tube
will
warm-up;
if
not
replace,
j
t
)pen R
104;
Shorted
C219
Nieck
and
replace
if
necessary.
j
Constant
percentage
error
t
in
output
voltage
)ut. of
calibration
Defective
R106
Recalibrate
per
paragraph
4-
14. 1
Check
and
replace
if
necessary.
j
Percentage
error
over
part
of
range
or
Output
erratic
1
over
part of
range
Defective
wi
rewound
resistor
n
the
sampling
string.
Rl
07
thru R140)
Set
the
output
voltage
to a
maximum
and
I
decrease
one
switch
position
at
a
time
untiL
J
the
error
disappears.
The
defective
resistor
will
be
found
at
the
last
switch
position
in
which
the
error
was
noted.
j
Output
erratic
over
entire
range
Defective
V202
Defective
output
voltage
switch,
or
dirty
switch
printed
circuit
board.
Test
and
replace
if
necessary.
Replace
switch,
clean
printed
circuit
board.
j
1
Defective
R104
or R106
Check
and
replace
if
necessary.
Output
rises
to
over
10KV
and
follows
line
voltage
variations
Defective
V202,
or
Q208
thru
Q214
Open
sampling
resistor
or
switch
Test
and
replace
if
necessary.
j
Test
R107
thru R140,
and S3
thru
S6,
and
J
replace
if
necessary.
Poor
load
regulation
Defective
Q208
thru
Q214
Check
and
replace
if
necessary.
Output
voltage
suddenly
I
rises
above
preset
value
Internal
arcing
in V202
Check
and
replace
if
necessary.
Noise
in
output
Dirty
high-voltage
switches,
capacitors,
or
printed
circuit
boards.
Clean
per
paragraph
4-4.
I
Excessive
drift
Defective
V201,
Q213,
or
Q
214
Check
by
replacement.
Excessive
ripple
Excessive
ripple
in
+125V
auxiliary
supply
If
auxiliary
supply
ripple
exceeds
approxi-
mately
5
mv,
replace
defective
component.
Defective C219,
C5,
Q213,
or
Q214
Check
and
replace
if
necessary.
1 Loss
of
control
Open
R243
Check
and
replace
if
necessary.
Figure
4-1.
TROUBLESHOOTING
4-2