Power Supply Board Section - Panasonic UF-5500 Service Manual

UF-5500 / 4500

11.2.21. Power Supply Board Section

11.2.21.1. Key Components For Troubleshooting
Check the following parts first: F1, F2, D1, C5, Q1 and PC1.
This comes from our experience with experimental test. For example: power supply and lightning surge voltage test, with standing
voltage test, intentional short circuit test, etc.
Caution:
If you find a melted fuse in the unit, do not turn on the power until you located and repair the faulty parts (except for the fuse);
otherwise the fuse will melt again and you cannot pinpoint the faulty point.
In most cases, the symptom is that nothing is output. It is more likely that the fault is in the primary side rather than the secondary
side. Check the primary side first.
AC
Input
Input
Circuit
A-B Voltage Wave Form
0
C-D Voltage Wave Form
0
E-F
G-H Voltage Wave Form
0
Heat Lamp
HTRCTL
7V
GND
24V
Block Diagram
A
Rectifier
+
Circuit
Kick-on
C5
B
Voltage
R2
Circuit
R3
R4
R41
Triac
SCR51
DUMMY LOAD to check voltage
CN101
1
2
120
2W
5
7
T1
G
Converter
Circuit
C
Q1
D
Control
Circuit
E
・O.C.L
H
F
Error Detecting
Circuit
PC1
Photo Triac
Coupler PC2
When you check voltage in
a power supply unit alone,
use this dummy load.
If the dummy load in not
available, connect the main
P.C.B. to the analog P.C.B.
V 6~8V
V
21.6~26.4V
220
5W
198
F101
24V
+
7V
+
GND
GND
HTRCTL
: Volt Meter
V