Daewoo KOR-868G Service Manual

Contents

Daewoo KOR-868G Service Manual Manual pdf 26 page image

251. CIRCUIT CHECK PROCEDURE1. Low Voltage Transformer check• The low voltage transformer is located on the P.C.B.• Measuring condition: input voltage : 120V/Frequency : 60Hz2. Voltage check• Key check point• Check methodPRINTED CIRCUIT BOARDNO CHECK POINT REMARK1 IC 1 PIN 2, 21, 30, 34 -5 VDC2 IC 1 PIN 353 IC 1 PIN 31 OR 32NOTE :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 Voltage4-7LOADAC 25.8 VNO LOADAC 28.4 VNO MEASURE POINT WAVE FORM REMEDY REMARK1 MP1 DC -5V±0.25V Replace VL1, EC1 NO LOAD2 MP2 DC -12V±2.0V Replace EC2, D12, 13, 14 NO LOADT:16.7ms(60Hz)T:250ns(4MHz)