8
3. RA-3/3A Power Supply Troubleshooting
C622
C624
R619
2
3
1
4
5
6
5
4
3
1
5
2
2
A BOARD
7
8
R654
C662
T604 PRT
D666
D603
C602
R610 R611
C620
IC601
MXO8
41AB-F
C612
N
2
1
RY601
12V
STBY
HOT
GND
R602
0.82
20W
Ω
C611
C612
P
12V STBY
Q651 BACK-UP
R668
D662
R617
C621
C623
2
IC654 DM-48
+135V
FROM IC001/62
CN1601
CN652
R677
R673
TO
PROT.
LATCH
Q652
RY
DRIVE
N
Q658
LIMIT
N
R681
R680
R679
D665
C673
R676
P
Q653
SOFT
START
R669
R666 C670
R670 C671
D668
24V
R683
R621
R618
D665
C659
C658
D658
R655
C664
D660
D659
R656
R652
T605
PIT
AUDIO
GND
AUDIO
B+
AUDIO
B-
+5V
-5V
+15V
-15V
18V
FIGURE 3-2 - SWITCHING POWER SUPPLY
AC
50V/DIV 5uS T/DIV
1/2W
Ω
R612 0.1
G BOARD
1TVP14 1448
7/17/02
IC652
IC653