Case Fan Plug Does Not Match Sys Fan

[Freerunner]

I'm trying to connect the case fans to my mb, but the female end from the fans only has accepts 3 prongs and the mb sys fan connection is 4 prongs. How do I handle this? The 2 items are:

GIGABYTE GA-AB350M-Gaming 3 (rev. 1.0) AM4 AMD B350 SATA 6Gb/s USB 3.1 HDMI Micro ATX AMD Motherboard

ROSEWILL ATX Mid Tower Gaming Computer Case, Gaming Case with Blue LED for Desktop / PC and 3 Case Fans Pre-Installed, Front I/O Access Ports (CHALLENGER)

 

[OmniDyne]

I'm trying to connect the case fans to my mb, but the female end from the fans only has accepts 3 prongs and the mb sys fan connection is 4 prongs. How do I handle this? The 2 items are:

GIGABYTE GA-AB350M-Gaming 3 (rev. 1.0) AM4 AMD B350 SATA 6Gb/s USB 3.1 HDMI Micro ATX AMD Motherboard

ROSEWILL ATX Mid Tower Gaming Computer Case, Gaming Case with Blue LED for Desktop / PC and 3 Case Fans Pre-Installed, Front I/O Access Ports (CHALLENGER)

The 3 pin fan connector will work with the 4 pin motherboard connector. You simply line up the tabs. One motherboard pin will simply not be utilized.

The photo looks similar to the connector for your case fans, right?

 

[Freerunner]

But won't I lose some functionality? If I am reading the instructions right for the mb, the pins represent the following; ground, voltage speed control, sense, and pwm speed control.

 

[OmniDyne]

You'll lose PWM.

Actually technically you're not losing anything, because fans with 3 pin connectors aren't capable of PWM. They'd have to be 4 pins and PWM capable.

All this means is that the fans will run full speed, and you will not be able to control their speed.

However, some motherboards are capable of controlling fan speed through 3 pins via voltage control, although that's usually on more expensive motherboards.

 

[Freerunner]

OK, thanks

 

[OmniDyne]

It appears your motherboard is voltage control capable.

 

[Freerunner]

One last question about the fans. The mb can handle 3 fans (including the cpu). However I have 3 fans in the case and cannot figure out how to connect the third one (it also has the 4 pin female as well as a larger 4 pin female, sorry I don't know the name of the cables, see picture). Where do I connect this fan?

 

[johnb35]

Some fans come with the 3 pin and a 4 pin molex connector. The molex is used when you don't have a fan header on the motherboard. So in your case if you have a motherboard header to attach it to then you don't use the 4 pin molex.

 

[Freerunner]

Nowhere on the mb can I see a spot for the molex. Any suggestions?

 

[johnb35]

If you don't have enough headers on the motherboard, you'll need to use a molex from the power supply.

 

[OmniDyne]

You'll see a connector similar to this one coming from the power supply.

 

[Freerunner]

Yep, got it, thanks