[SOLVED] Build questions - NZXT H510i

[paekivi]

Hello everyone!
I'm building my PC and need some answers for my problems, could not find the answers googling.

1. The front panel connector going to motherboard. I have to use a splitter and motherboard manual shows exactly which one goes where. But the problem is, on the splitting connector I have no idea which pin is + and which -. There is +P LED and -PLED which is fine. But POWER SW and H.D.D LED dont have those marks. Also both cables are black. There is an arrow on one of the pins, but no idea if it means + or -?

2. My AIO has 3-pin connector, but motherboard 4-pin. I understand that it is OK to connect, but which pins should I use?

3. My case has Smart Device V2, so 2 original fans connect there and 3 connectors come out, but I have not managed to find out where should I connect those on my motherboard?
Maybe someone has a build similar to mine and can be helpful?

Specs:
CPU: Ryzen 9 3900x
COOLER: EVGA CLC 280mm AIO
MB: MSI X570 A-PRO
RAM: G.Skill DDR4 32GB 3600MHz
Storage: ADATA XPG S40G 1TB M.2
GPU: Gigabyte Radeon 5700XT
Case: NZXT H510i
PSU: Corsair HX1200i 80+ Platinum
Thanks in advance!

 

[extreme_noob]

You're saying you had to use a splitter for the front panel headers?
There is only one physical way to connect a 3 pin fan cable into a 4 pin header, because of the small plastic piece which protrudes from the header.
As far as I know the smart device has a SATA power cable, which you plug into your PSU's SATA cable, and a USB 2.0 cable, which you plug into a motherboard USB 2.0 header.

View: https://www.youtube.com/watch?v=BHC8_sMgH5Q

GN did a video on the Smart Device V2, and basically said it's useless. I don't know if they updated CAM to make it more useful, but you're probably better off plugging the stock fans into the motherboard.