Sorry about the late reply.

I had two of these failed PSUs, and repaired one this weekend. (The other was used for spare parts.)

The problem is a failed MOSFET on the secondary, which fails short. Thankfully the PSU has short circuit protection, that's why you hear the click. Check the output with a multimeter, you will likely see a shorted output. If so then the fault is most likely one of these MOSFETs.

This can be repaired pretty easily with a hot air rework station, some experience doing these sort of repairs, and some patience as the MOSFETs are pretty solidly soldered to the board and surrounded by large copper planes. An easy way to check to see which MOSFET failed is to probe between the gate and the drain or source (just use a nearby heatsink); the failed MOSFET will show ~4.4ohms lower, as the working units will pass through two 2.2ohm resistors in series, the failed one will be low impedence to the source and drain. I took a working MOSFET from one failed PSU and transplanted it into another, and now I have a working PSU and another PSU for spares.

If you don't want these PSUs and still have them I can buy them, or if you have multiples I can repair them but cannot guarantee how long they will work with the stock MOSFETs, they seem to be trash. I haven't checked for what replacements will work for quality MOSFETs or the cost. Other than the shoddy MOSFETs the PSU is built decently enough.