Daewoo KOG-6CDB5S, Service Manual, Page: 28 / 36

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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
2. Voltage check
• Key check point
• Check method
PRINTED CIRCUIT BOARD
NO CHECK POINT REMARK
1 IC1 PIN 5 5 VDC
2 IC1 PIN 8
3 IC1 PIN 35 OR 36
NOTE :
Each measure point must be measured with GND points.
NOTE :
1. Refer to Circuit Diagram (point 4).
2. Secondary side voltage of the low voltage transformer changes in proportion to fluctuation of power source voltage.
3. The allowable tolerance of the secondary voltage is within ± 5% of nominal voltage.
Terminal Voltage
4-7
LOAD
AC 12.6 V
NO LOAD
AC 14.7 V
NO MEASURE POINT WAVE FORM REMEDY REMARK
1 MP1 DC 5V±0.25V Replace VL1, EC1 NO LOAD
2 MP2 DC 12V±2.0V Replace EC2, D12,13,14 NO LOAD
T : 20ms(50Hz)
T : 250 ns(4MHz)