Fried my first card last night -
https://imgur.com/a/I8Nh4Turns out you're not supposed to connect anything else to the molex cable that's going into the add2psu, also you're supposed to power all risers with the primary PSU, any other tips/tricks y'all know of?
the seconday psu connects its 24 pin into the add 2 psu. the main psu connects into the molex. how it work is, when the main psu cuts power, the add 2 psu sends that signal via the 24 pin mobo cable to the 2ndary psu. another point to note, you can control on the add2psu the amount of time you want before the 2ndary psu cuts off. i believe its btwn 1-5 seconds. not too sure. i use something like this
https://www.amazon.com/Motherboard-Adapter-Machine-splitter-TeamProfitcom/dp/B074QNMRSTworks very well for me. i also power the risers and card via the same psu. i believe you can power the risers and mobo via a main psu, and power your gpus via a 2ndary gpu.
good luck, and stay safe brother. last thing you want is a fire.