I had a good look on them and they are immaculate, no sign of any burn or crack.
Here is a picture of it, this is how I connected them. These are the components in order:
1. Delta power brick -> 8-pin Mini-Fit Jr. male output
2. 16-pin Mini-Fit Jr. female input -> DC male barrel output
3. DC female barrel input -> 4-pin Mini-Fit Jr. male output + grounding ring
4. DC 12V 4-pin Mini-Fit Jr. female input on the PSU board (not seen on above pic.)
I just put them together where they fit and clamp. There is only 1 way to connect them due to the shape of it.
I don't have model/pinout for them. The power brick's exact type is Delta EADP-220AB B.
I gotta get a multimeter, but I'm clueless about how to use it... Know any good guides I could look at to make sure I'm on track?
I've plugged the 4-pin power connector to the top right corner, where it says DC12V input. I triple checked this before proceeding. I didn't use the other 4-pin for CPU, because the MBD has iCPU.
Thanks a bunch for all the help, everyone! It really means a ton. 
