[SOLVED] Trying to make sense of my case fans...

[123321]

My case (local unknown brand) came with 3 case fans. Each one has 3 cables on it: 4 Pin Molex, 2 Pin Molex, and a 3 Pin DC connector.

• Plugging only the 4 Pin Molex straight into the psu runs the fans but leaves the RGB off.
• Plugging only the 3 Pin DC to sys_fan1 on the mobo makes both the fans and RGBs run. RGBs flash an ugly unsynchronized preset color pattern though.

(Found this other thread which looks very similar to my issues: https://forums.tomshardware.com/thr...-second-while-booting-then-turns-off.3561245/)

I've been trying different ways to plug these guys in such that I can control the RGB but can't seem to find a way... Does anyone know what kind of fans these are and how to make them work properly?

 

[RamboRyza]

Hi there,

Strange that they gave you a 2 pin molex for each fan...

So the 2 pin molex is for the RGB for each fan. It effectively provides the RGB power from the PSU therefore only needs 2 pins.

The 4 pin is for when you want your fans to run at 100%. You just plug in the 4 pin molex and away they spin.

The 3 pin to fan header is for PWM, although normally they are 4 pin. You may have control over these or not, depending on whether your board supports voltage control for 3 pin. They may just run at 100% anyway.

So, you will want to plug in every 2 pin molex (for your RGBs) and the 3 pins to your mobo fan headers for power. Or the 4 pin molex.
Choose between 4 pin to molex for 100% power, or 3 pin to mobo fan headers for potential control. NOT BOTH THE 4 PIN MOLEX AND 3 PIN HEADERS. May cause damage.

This should be the setup. If you have ANY confusion with what I've said, let me know. You need to make sure it's right and you haven't got your PSU linked to your mobo via molex, bad bad.

Hope this helps mate.

 

[madmatt30]

What case and fans?? Link to it

With those connections any kind of colour control or syncing is impossible unless your case has a rgb controller built in.

 

[123321]

Hi there,

Strange that they gave you a 2 pin molex for each fan...

So the 2 pin molex is for the RGB for each fan. It effectively provides the RGB power from the PSU therefore only needs 2 pins.

The 4 pin is for when you want your fans to run at 100%. You just plug in the 4 pin molex and away they spin.

The 3 pin to fan header is for PWM, although normally they are 4 pin. You may have control over these or not, depending on whether your board supports voltage control for 3 pin. They may just run at 100% anyway.

So, you will want to plug in every 2 pin molex (for your RGBs) and the 3 pins to your mobo fan headers for power. Or the 4 pin molex.
Choose between 4 pin to molex for 100% power, or 3 pin to mobo fan headers for potential control. NOT BOTH THE 4 PIN MOLEX AND 3 PIN HEADERS. May cause damage.

This should be the setup. If you have ANY confusion with what I've said, let me know. You need to make sure it's right and you haven't got your PSU linked to your mobo via molex, bad bad.

Hope this helps mate.

Thanks for the reply! Connecting both the 2 Pin and 4 Pin Molex straight to the psu gives me the same result as connecting only the 4 Pin Molex to the psu (Fans work but not RGB). Connecting the 3 Pin to the Mobo turns on both the fans and the RGB and lets me control fan speed via the BIOS but not the RGB colors/pattern

 

[123321]

What case and fans?? Link to it

With those connections any kind of colour control or syncing is impossible unless your case has a rgb controller built in.

Thanks you for replying

Here is the case: https://hongredtech.ph/computer/casing/viking-vks34-shield-tempered-glass-rgb-gaming-case/

I suppose you're right and these fans are a lost cause hahaha... I was kinda hoping for some sort of last resort work-around because it seems like a waste to replace these guys just to make the RGBs pretty haha

 

[RamboRyza]

Thanks for the reply! Connecting both the 2 Pin and 4 Pin Molex straight to the psu gives me the same result as connecting only the 4 Pin Molex to the psu (Fans work but not RGB). Connecting the 3 Pin to the Mobo turns on both the fans and the RGB and lets me control fan speed via the BIOS but not the RGB colors/pattern

What about 3 pins to mobo, and 2 pins to PSU? Can't see the 2 pins adding RGB control but i don't think you've got that anyway unless there is a program you use to control them in the OS. Madmatt30 is on the money there I think.

Otherwise just the 3 pins will be the go.

Can't believe they gave you 6 molex for 3 fans hahaha

 

[madmatt30]

So is there a button on your case for any kind of rgb control??

Can you upload a photo of the 3 pin connector??
I don't understand how it could be possible to control the rgb with these connections.

I also don't understand why there is a 2 pin as well as a 4 pin molex.

It kind of makes no sense at all.

 

[123321]

What about 3 pins to mobo, and 2 pins to PSU? Can't see the 2 pins adding RGB control but i don't think you've got that anyway unless there is a program you use to control them in the OS. Madmatt30 is on the money there I think.

Otherwise just the 3 pins will be the go.

Can't believe they gave you 6 molex for 3 fans hahaha

3 Pin to mobo, 2 Pin to psu has the exact same result as just 3 Pin to mobo. I am starting to think that these 2 pin connectors don't do anything at all haha

Unfortunately, I can't find any information on these fans online, much less a driver that can control its RGB 🙁

 

[RamboRyza]

Hmm sorry mate, I'm out of ideas right now.

Upload a pic of your fan connections if you can. Will have a look and maybe something will click.

Cheers!

 

[123321]

So is there a button on your case for any kind of rgb control??

Can you upload a photo of the 3 pin connector??
I don't understand how it could be possible to control the rgb with these connections.

I also don't understand why there is a 2 pin as well as a 4 pin molex.

It kind of makes no sense at all.

The case only has a power button and a reset button.
Here is a photo of the 3 Pin

https://imgur.com/a/FdY2jfN

View: https://imgur.com/a/FdY2jfN

 

[123321]

So, first of all, thank you for the replies 😍

I think I found a work-around by fiddling with whatever I could in the BIOS (which is just voltage control really). Just in case anyone else bought this cursed case, here's what I did... By dropping the fans to below 4V, they barely have enough power to keep spinning at low rpm. This also makes the RGB not have enough power to cycle through the ugly patterns and they stop at a steady, dim red.
Here's how they look now:

https://imgur.com/a/ogV0in6

View: https://imgur.com/a/ogV0in6


It's not perfect, but it looks better than the default cycle imo. Since I imagine capping the front fans at 4V hurts my temps, I set the smart fan control to set the fans to 100% if my CPU goes above 55C. This turns the ugly RGB back on during heavy load but at least they're not always on haha

 

[RamboRyza]

Good to hear! (sort of I guess)

 

[Paperdoc]

WARNING! Do NOT use what one person advised above. This is about connecting both Molex and 3-pin fan connectors at the same time.

What I suspect you have is a type of 3-pin fan with added RGB features. Some such fans come with both a 4-pin Molex and a 3-pin female fan connector so that you can use ONE of those, but NEVER both. IF you have the 3-pin plugged into a mobo fan header supplying a reduced voltage for a particular fan speed AND you then plug the male (with pins) Molex into a PSU output, that will force the full 12 VDC back into the mobo fan header and may damage it permanently! So do NOT do that! Many such fans also connect a second FEMALE Molex connector so that you can plug another fan into that, instead of into a PSU output.

With such an arrangement, there is no way to control what the RGB lights do. I would have expected the designers just to connect the lights in parallel with the fan motor, and MAYBE to provide some fixed circuit to vary the lighting pattern. But why your fans do NOT provide lights when powered from a Molex source I do not understand.

 

[RamboRyza]

WARNING! Do NOT use what one person advised above. This is about connecting both Molex and 3-pin fan connectors at the same time.

What I suspect you have is a type of 3-pin fan with added RGB features. Some such fans come with both a 4-pin Molex and a 3-pin female fan connector so that you can use ONE of those, but NEVER both. IF you have the 3-pin plugged into a mobo fan header supplying a reduced voltage for a particular fan speed AND you then plug the male (with pins) Molex into a PSU output, that will force the full 12 VDC back into the mobo fan header and may damage it permanently! So do NOT do that! Many such fans also connect a second FEMALE Molex connector so that you can plug another fan into that, instead of into a PSU output.

With such an arrangement, there is no way to control what the RGB lights do. I would have expected the designers just to connect the lights in parallel with the fan motor, and MAYBE to provide some fixed circuit to vary the lighting pattern. But why your fans do NOT provide lights when powered from a Molex source I do not understand.

Thats what I said mate, only 3 pin to fan header OR 4 pin molex to PSU,

BUT the OP said each fan has a 4 pin molex and a 2 pin molex, indicating they are both male, they apparently have no female molex at all.

Molex FROM PSU are always female. And TO are always male. Which indicates that either one or both of the molex MUST run TO the PSU in some fashion.

I still think the 2 pins are for RGB power, and the 4 pins are for 100% (if chosen instead of 3 pin).

But why it's not working properly doesn't make sense...

 

[Paperdoc]

I am not sure the term "4-pin" means it IS the male. Many use that term for either gender of connector, and specify gender separately. But at least those connectors do have pins and holes - some, like the SATA system, make it much more difficult.