Shorting an AC adaptor's output
You said:

I really haven't a lot of experience with AC PSUs yet...

Beware! PSUs can cause fire, explosion, property damage and personal injury etc. (not just from electrocution, but indirectly too e.g. a loud &quot;bang&quot; can cause a person to quickly move their hand away and then impact their hand against other objects, causing injury). I recommend you research about relevant safety precautions for working on such PSUs - that is a whole topic on its own.  Using any information I have given is completely at your own risk.

In your photos of that PSU, I can see 3 points worth mentioning, which I have marked on this version of your internal photo:


As kindly commented by Spehro Pefhany, on the right appears to be a round, 2 A, time-delay (slow-blow) mains input fuse, designated F1 on the PCB.

Close to that fuse, and only on that photo (not on the photo showing the reverse side of the PCB, for example) there appear to be 2 unexpected component leads or wires. This is a concern.

Not yet mentioned, and very relevant since you shorted the output, is that there appears to be a rectangular, 4 A, time-delay (slow-blow) fuse on the output, designated F2 on the PCB. Obviously that should be checked for continuity (as should mains input fuse F1, but output fuse F2 is a more likely candidate for having blown, after the output was shorted as you describe).


Only replace any blown fuse with a functional equivalent, and never with a piece of normal wire. If the replacement fuse blows, than there is a further fault which will need to be investigated (or further repair attempts could be abandoned at that point).