Racal Instruments 9901 Maintenance Manual page 57

FUSES
5.3
(1)
Check
thaf
fhe
power
fuse
on
the rear panel
is
correctly rated
for
the
supply voltage,
as follows.
The
fuse
is
a
glass cartridge type,
5 x 20
mm.
Supply Range
Fuse Rating
Racal Part
No.
188V
to
265V
94V
to
132V
100
mA
anti
-surge
23-0033
200
mA
anti -surge
23-0027
POWER
LEAD
5.4
Fit
a suitable plug
to
the
power
lead
in
accordance
with the standard colour
code:
-
Brown
Line
Blue Neutral
Green/Yellow
.... Earth
(Ground)
POWER
SUPPLY
CHECK
5.5
(1)
Remove
the covers
and
prepare the
power
supply
as
described
in
the
preceding paragraphs.
Check
that the
a.c. supply voltage
is
correct.
(2)
With power
supply connected, switch
POWER
to
ON.
(3)
Using the multimeter (Page 5.1, Table
6,
item
1)
check
the
d.c. voltages
at the Following points
on
the
main p.c.b.
Fig. 3 at the
back
of the
book
shows
the
component
layout.
Test Point
Measurement
Remarks
TP7
+5.1V±0.3V
)
Relative to chassis.
TP6
-5.
IV
±
0.4V
)
NOTE;
There are no adjustments
in
the
power
supply
circuit.
If
the
5V
supplies are outside the
limits
given above,
the
mains
supply voltage
and
the transformer
line
lead
connection and
links (see
page
5-3) should
be
carefully
checked.
If
these are
correct the zener
reference diode
DIO
should
be checked.
9901 Vol. 2
5-4