PRINTED CIRCUIT BOARD
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 | LOAD |
| NO LOAD |
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AC 12.6 | V | AC 14.7 V |
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.
2.Voltage check
Key check point
NO | CHECK POINT | REMARK |
1 | IC 1 PIN 5 | 5 VDC |
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2 | IC 1 PIN 8 |
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T:20ms(50Hz)
3
IC 1 PIN 35 OR PIN 36
T:250ns(4MHz)
Check method
NO | MEASURE POINT | WAVE FORM | REMEDY | REMARK | |
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1 | MP1 | DC | 5V 0.25V | Replace VL1, EC1 | NO LOAD |
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2 | MP2 | DC | 12V 2.0V | Replace EC2, D11, D13, D14 | NO LOAD |
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NOTE :
Each measure point must be measured with GND point.
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