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How To Repair Dc Regulated Power Supply
- Jun 07, 2018 -

How to check and repair one dc power supply the voltage could not work?

When one dc power supply the voltage could not work normally.

The most because of the voltage potentiometer or its PCB has problem.

Now let us to see how to check it.

Before check the power supply:

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Before test it,we need to adjust the right 2 voltage potentiometer by anticlockwise to the Minimun value,then use the multimeter ,then it will show 5.1V.

Then ,use the multimeter,test the 1st and 4th wire as above picture showed.

Test result will show as follow:if show like this ,that is no problem.

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Sencond,before test it, 1st and 4th wire ,we need to adjust the right 2 voltage potentiometer by clockwise to the Maximun value,then use the multimeter ,then it will show 0V.

as follow:

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if test the result like this ,that is no problem.


Above showed how to test the voltage potentiometer.



Now show how to check the potentiometer PCB:

Turn the two potentiometers of regulating voltage clockwise to the maximum, and turn the multimeter to the measuring gear of the diode, as shown in the figure below:


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  1. The double-connected 1K potentiometer is measured here with a large resistance value




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2.The double 1K potentiometer is measured here and the resistance value is large




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3.The single 10K potentiometer is measured here, and the two points are on (the resistance value is infinitesimal).



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4. The resistance value of the single 10K potentiometer is relatively large



Potentiometer board detection (according to the chart, it is good if there is no break between two points)


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