How to test this regulator ic and associated components?

 

Your part-number seems to be invalid.

Please provide a Spec-Sheet for your part.

Most Data-Sheets have Schematics showing exactly how the manufacturer's Specifications were arrived at,
You can easily duplicate these test Circuits for yourself.
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Hello,

Do you mean the KA5Q0765RT?
https://www.alldatasheet.com/datasheet-pdf/pdf/53231/FAIRCHILD/KA5Q0765RT.html

Bertus

 

Assumption: You have a dead power supply. You have limited test machines. It really is a KA5Q0765RT.

Pins 1&2 have a large gap. There is a MOSFET D-S across those two pins. It should test like a power diode. If the part died from too much current or too much voltage, there might be a short from 1-2. That is a bad sign.

Please do not plug the supply into the wall and test things without experience. There are more tests but we need to know if this is a power supply first.
RonS

 

How to test this regulator ic and associated components?

First of all, welcome to AAC!
Second, most of the participants are unable to perceive what a Thread Starter, (TS) is thinking without the TS providing an adequate question. Without an adequate question you can only expect random guesses. If the initial request was intended to include an attachment or a link, that did not happen.