How to troubleshoot broken adapter?

Hi guys,

My Macbook adapter is not working. When I plug it on both ends, nothing happens, no light, nothing.

I opened it, and tested voltage with a voltmeter at the output of the circuit, at the start of the wire, and it's 0.

It thus seems that the problem is inside the circuit.

Here's a picture of it. Not sure whether it looks normal or not.

By now I have cut the cable off the case, and tested with a multimeter voltage at the output of the case. It is 0.5 V. Thus the case circuit itself is broken, I am looking for how to fix it.

After a while, I might have additional insights as to what might have caused the problem. It seems that the cable itself was shorted. Meaning that when I cut the cable off the case, and tested for continuity on both wires of the cable alone, my multimeter beeped. Thus I am assuming that the way the adapter itself was damaged was because its two output wires were connected to each other.

Any idea how I can troubleshoot it and potentially fix it ?

Thanks in advance !