Trouble-Shooting The Power Supply; P.c.b. Interconnections - Philips PM3055 Service Manual

14-11
14.5.4
Trouble-shooting
the power
supply
To determine whether
a
certain
fault condition
is initiated by
the
power supply itself or by the connected oscilloscope
circuits,
a dunimy
load
is listed
in the
table below. The table gives also an example of
the resistor
types that can be used to compose the dummy load.
These resistors can be ordered
at Concern Service.
Supply
voltage
Output
current
Dummy resistance and their
service ordering numbers
+
5
V
2,4
A
2,1E-12W:
3
X 8E (4822 112 21052) and
lOE (4822 112 21054) in parallel.
-
6,4 V
930
mA
6,9E-6W: 8,2E (4822
112 41052) and
47E
(4822 110 23072) in parallel.
+ 12 V
720
mA
17,2E-8,7W: 33E (4822
112 41067) and
39E (4822 112 43069)
in parallel.
- 12
V
500
mA
24,7E-6W: 39E (4822
112 41069) and
68E (4822
112 41067)
in
parallel.
+
17
V 340 mA
51E-6W:
IE
(4822 110 23027)
in
serial with
2
X 100 E(4822
112 41081) in parallel.
-
17
V
100
mA
171E-1,7W: 270E (4822
110
43092)
and
470E (4822
110 43098) in parallel.
+ 48 V
140 mA
341E-7W; 330E (4822
112
41094)
in
serial
with 12E(4822
110 23056).
-
48 V
40 mA
Ik22-2W: 2k2 (4822 110 23116) and
2k7 (4822
no
23118) in parallel.
14.5.5
P.c.b.
interconnections
Figure
14.5 gives
a
survey
of all
interconnections between
the
p.b.c.'s
and to the CRT. Also
the interconnections between
the
connectors
on
board
level
is
given
in this diagram.
An explanation
of the
connector indication
is
given below:
*:
Input signal for the related
p.c.b.
o: Output signal
for the related
p.c.b.
x:
Interconnection between
two or
more sockets
of the p.c.b.
Not used on the related p.c.b.
signal name
input /out
put
indication
connector pinning
1
2
o
3
X
4