33
12. PRINTED CIRCUIT BOARD
CIRCUIT CHECK PROCEDURE
1. Low voltage transformer check
The low voltage transformer is located on the P.C.B.
Measuring condition: Input voltage: 230V / Frequency: 50Hz
2. Voltage Check
- Key check point
- Check method
NOTE
1. Secondary side voltage of the low voltage transformer changes in proportion to fluctuation of power source
voltage.
2. The allowable tolerance of the secondary voltage is within ± 5% of nominal voltage.
NOTE: Each measure point must be measured with GND points.
Terminal
6-10
Voltage(olad)
DC 13V
Voltage(no load)
DC 14V
NO
CHECK POINT
REMARK
1
IC1 PIN 55, 64
5VDC±5%
2
IC1 PIN 17
3
IC1 PIN 30 OR 31
T : 20 ms(50Hz)
5V
0V
T
T : 250 ns(4MHz)
5V
0V
T
NO
MEASURE POINT
WAVE FORM
REMEDY
REMARK
1
A
DC 5V±5%
Replace C13, C3
NO LOAD
2
B
DC 17V±20%
Replace D10~D13, EC4
NO LOAD
3 4
5
10
LVT1
DMR-621FS
AS 230V/50Hz
6
Summary of Contents for KOC-624Q0S
Page 31: ...30 10 WIRING DIAGRAM ...
Page 38: ...37 13 P C B CIRCUIT DIAGRAM ...
