Thanks for the advise. I think I will have to cut the cable ties to try and find what’s going on. I’m guessing if I remove the old unit from the back that would have been connected to a sata port?You can leave the old one in place if there's room, but I know it's a very tight space at the back of that case. However you'll want to move the cables (RGB that are connected to the current node & PWM that will be connected to the motherboard) over to the new controller.
There should be a spare SATA power socket (or a splitter / molex convertor) to connect to, but I've not got that PSU and it's a relatively low power one so will have fewer outputs than the higher power ones. You may have some spares in the PCS box that came with the PC.
Also, is there going to be only one PWM at the front? I’m guessing these cables will be coming from the front fans?