I got a power-supply gifted by my friend. When I powered ON, the main (120V) FUSE blows up. I started by disconnecting the transformer from the control circuit and powered ON. This time the fuse is NOT BLOWN. This points to the control circuit as the source of the short.

Then I checked the bridge using the multi-meter and it looks good.

From here I don't know how to proceed...

Below is the link for the circuit


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    $\begingroup$ When you write that you've disconnected the transformer - you mean from the mains (primary side) or from the rest of the circuit (secondary)? Edit your question and include a marked up schematic to help us out. $\endgroup$
    – mike65535
    Apr 24 '19 at 13:49
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    $\begingroup$ So you disconnected the transformer so that it's standing by itself? AC mains on one side and the secondaries just hanging in the air? And when it's like that the fuse doesn't blow? I don't see how that at all rules out the control board, unless I misunderstood what you said. $\endgroup$
    – Duston
    Apr 26 '19 at 16:24
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    $\begingroup$ Ok. After reading more about the circuit and analysis, I found out it is the BRIDGE which caused the problem. I replaced it. $\endgroup$
    – Raajkumar
    Apr 29 '19 at 15:47
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    $\begingroup$ @Raajkumar If you've solved your problem, please post an answer explaining how you identified the bridge as the cause. $\endgroup$
    – Kevin Reid AG6YO
    Apr 29 '19 at 16:46
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    $\begingroup$ To clarify @KevinReidAG6YO 's comment, comments are not for posting answers to questions. If you post an answer explaining how you identified the bridge as the cause, then it can be upvoted and you'll gain more rep points. You can even mark your own answer as accepted. :-) $\endgroup$
    – Mike Waters
    Apr 29 '19 at 20:14

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