Daewoo KOG-371G0S Service Manual page 61

PRINTED CIRCUIT BOARD <KOG-376T1S, KOG-396T1S>
1. 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
Terminal Voltage
8 - 9
6 - 7
NOTE
1. Refer to Circuit Diagram (point 4).
2. Secondary side voltage of the low voltage trasformer changes in proportion to fluctuation of power source
voltage.
3. The allowable tolerance of the secondary voltage is within 5% of nominal voltage.
2. Voltage Check
- Key check point
NO CHECK POINT
1 IC1 PIN 6, 10, 11
2 IC1 PIN 22
3 IC1 PIN 8 OR 9
- Check method
NO MEASURE POINT
1 MP1
2 MP2
NOTE
Each measure point must be measured with GND points.
LOAD
AC 23V
AC 2.27V
-5VDC
WAVE FORM
DC -5V±0.25V
DC -24V±2.0V
60
REMARK
REMEDY
Replace VL1, EC1
Replace EC3, D8-11
NO LOAD
AC 27.7V
AC 2.79V
T : 20ms(50Hz)
T : 250 ns(4MHz)
REMARK
NO LOAD
NO LOAD