Rosewill case fan converted to 4 pin

[meares44]

I have been trying to figure out a way to use my rosewill RGB case fans with Asus aura sync. At first the fans appear to be 6 pin but a closer look reveals only 5 in use. After playing with a volt meter I found 2 pins were positive ans the other 3 (the RGB) were negative. If I was to tie the 2 positive wires together and solder to a 4 pin plug would they work with Asus aura sync? Would fan speed still be able to be controlled?.

 

[Aeacus]

With little to no knowledge about the fan pinout, you'll risk frying your fan or at worst case scenario, brick your MoBo as well. Rather than jerry-rigging and soldering fan pins together, buy a RGB fan that is certified to work with Aura Sync,
link: https://www.asus.com/campaign/aura/us/Partners-and-promotions.html
(select Cooling tab)

As far as RGB fan pinout goes, minimum you're looking at would be 5x pins with 2x of them for fan speed and 3x of them for LEDs. E.g like so:
fan control:
pin #1 - +12V
pin #2 - ground
LED control:
pin #1 - +12V
pin #2 - red
pin #3 - green

Also, if you solder all those connectors to a single connector, how you're planning to control LEDs and fan speed at the same time? MoBo has separate headers for fan speed and RGB control where both are usually 4-pin connectors. Also, MoBo can't control LEDs when fan is plugged to the fan header and same is vice-versa, where MoBo can't control fan speed if fan is plugged to the RGB header.

MoBo side pinout is as follows:
fan control:
pin #1 - +12V
pin #2 - ground
pin #3 - sense (fan RPM feed back to MoBo)
pin #4 - PWM
RGB control:
pin #1 - +12V
pin #2 - red
pin #3 - green
pin #4 - blue

 

[meares44]

Yeah after staying up late last night playing with one of the fans the fan hub a volt meter and some resistors I think buying replacement fans that are Asus Aura Sync comparable is probably what I will do. I am building this computer with and for my 11 y.o. daughter. We are already WAY over budget (lol don't tell mom) but I want everything to work perfectly for her and for her to learn the right way to build. It has been a few years since I built one and RGB wasn't a thing so I should have read more about it before I started buying things

 

[Aeacus]

Before buying any component, make a list of all you need. Also, if you can't figure the list out, make a topic here in Tom's Hardware forums. We have plenty of experts around who can give you the best performance with the money you have. You might even find interesting new components that you never knew existed.
You can use PCPP to keep a list of your components which also includes lowest purchase prices, depending on your criteria,
link: https://pcpartpicker.com/list/

As far as my own PCs go, i have 3x of them: Skylake, Haswell and AMD. You can see them all from the 3x links in my signature which also include full specs (with component buying prices), story behind each PC with build logs and lastly, pics as well.

Btw, at current time, best way to learn building a PC and without risk of breaking a wallet is via a game called PC Building Simulator,
steam link: https://store.steampowered.com/app/621060/PC_Building_Simulator/

While building a PC in real life is more complicated, that game gives a good idea to anyone who doesn't know how PCs are put together. Game also includes troubleshooting on software and hardware level, though more simplified than in real life.