So yesterday I got my power supply in the mail and I thought, let's check it out!
I put all the wires in correctly (as shown in this YouTube video, Anet A8 power supply unit fuse blown, I just searched really quickly, this person has the same problem as me) and "BANG", it blew.
Luckily the only thing broken on it is the fuse, for which I can get a new one, but my main question is .. why? why did it blow out? Did I wire it up wrong? The 12 V output goes to a RAMPS 1.4 board which is working correctly.
It worked the first time I plugged it in; the little green light went on. The second time a nice "big bang". When I tested it the first time, I didn't add the 12 V wires to the RAMPS board yet. When I did, the fuse of the PSU blew out.
The board is a RepRap RAMPS 1.4, which works fine when connected via USB to laptop.
Upon closer inspection I found a burned out resistor in the circuit of the power supply, maybe this caused the bang?
BIG update!
I opened it up and flipped the board, and noticed that there was a big ol' blob of tin connected to one of the pins I connected my wires to. I am very sure that this blob shouldn't connect to that pin at all, hence shorting my board.
Is this the cause?
Here is a link to the webpage I bought it from: Anet® 12 V 20 A 240 W Power Supply Dual-input Centralized Power Monitoring For 3D Printer
Here is how I wired it up at the PSU side:
At the RAMPS side:
This shows the internals of the PSU, it clearly shows burn marks: