Way to power extra fan no more room on motherboard

[ghost101]

I am needing to install a 160mm fan and have no spot on my MB to power it (3 pin) does anyone know of a converter to power it by USB or something? I already have the fan, it is red led that I wanted but I am ok buying another fan if it has red led as well. I just need a way to power it on, I would get a fan controller but not really needed for just one additional fan.

 

[ghost101]

Also, is there a way to power off USB items plugged into the computer without switching the PC switch off? I noticed my accessories still remain powered when the PC is off.

 

[Paperdoc]

There are two solutions available.

One is, you buy an adapter that allows you to plug this 3-pin fan directly into a 4-pin Molex output connector from the PSU. This will make that fan run at full speed all the time, AND there will be no way to read its speed.

Second option is to buy a 3-pin fan splitter adapter that lets you plug two fans into one mobo port. Then you can plug this fan plus one you already have connected into the SYS_FAN port already in use. Or, you could connect two of your existing fans together on one port, freeing up a port for use with this large fan. Either way the fans all become speed-controlled, with speed readout possible for the fans. (Well, actually, on the port with the adapter and two fans, only one of those fan's speeds will be readable.) Most mobo fan ports can handle two fans, but not more.

 

[ghost101]

No way to USB it?

 

[Paperdoc]

Powering this fan from a USB2 port will not work. A USB2 port can supply to its connected device a maximum of 0.5 amps at 5 VDC. Your fan is designed for a supply of 12 VDC, with a heavy start-up current for a second or so. If it is given only 5 VDC, it may not start up at all. Even if it did, it would only run at very low speed. And you would have no control over its speed. I don't now whether the red LEDs in it would work or not.

I have never seen an adapter to power a 12 VDC case fan from a 5 VDC USB port.

 

[ghost101]

There is a spare cord with 4 pins (mirco 4 pin?) that is used to light up the LED on the case. Is there a way to convert this to a 2 or 3 pin fan? What if I use a smaller fan? I have the asus g20 which I customized the chassis outside the GPU to better venting, but I am very nervous to dig through the pre-build system to find a spot for the fan...

 

[ghost101]

Would something like this work?

http://www.aliexpress.com/store/product/5-Pcs-GDT-PC-Cooling-Fan-2510-4P-Female-to-Dual-2510-4P-Male-Y-Splitter/1017947_1835274068.html

I am not sure if this is the right 4 pin cord I have, but it is used in the chassis to power a LED lighting effect, I am only using one of them and there are two. Could I convert one to a fan with something like this?

 

[Dark Lord of Tech]

http://www.newegg.com/Product/Product.aspx?Item=N82E16812493031

 

[ghost101]

Again, I do not have access to the cords aside from the Micro 4 pin thing I mentioned. The link to NewEgg provides no information on what I can do externally or with a 4 pin micro. I have the Asus G20,

http://www.profesionalreview.com/wp-content/uploads/2014/12/asus-rog-g20-review-16.jpg

I do not feel comfortable taking this apart

 

[Paperdoc]

What you need is similar to that, but not exactly that for two reasons:

1. That's a 4-pin fan splitter adapter. You have a 3-pin fan, you said. If you connect a 3-pin fan to a 4-pin mobo port, the fan will always run at full speed - the mobo will not be able to control it.
2. That adapter as pictured has yellow wires connecting the speed pulse pins of all connectors together, which will deliver a double set of speed signals to the mobo causing it confusion.

Ideally you want a 3-pin fan splitter adapter with the yellow wire going to only one of the two (male) output connectors, like this one:

http://www.newegg.com/Product/Product.aspx?Item=N82E16812423168&cm_re=3-pin_fan_splitter-_-12-423-168-_-Product

Note the detail about connections in the Specifications section. If you use this type of splitter to connect two 3-pin fans to one 3-pin fan mobo port, they will work just fine.

 

[ghost101]

Ok but we are still back to the problem of having access to a USB port and the micro 4 pin cord that is available. I can not get to the mother board, and if I did my knowledge with it is limited and I fear i wont locate the correct spot to plug in the fan.

Again, I have the Asus g20 desktop

 

[ghost101]

Here is a picture if you manage to get below the aluminum barricade, can anyone point out where I would plug the fan in at? Or if I need a 3 or 4 pin fan?

http://prohardver.hu/dl/cnt/2014-09/111961/pic/asus_rog_g20_inside2_s.jpg

 

[Paperdoc]

OK, now I'm getting it. This is a complete gaming machine with an unusual mobo and case. It was not designed for users to open it up and change components. I could not find details of that mobo on the internet - only similar ones designed differently. Result is I cannot spot on the picture where the mobo's fan ports are. So I can't even tell if they would be 3-pin or 4-pin. Maybe you can find them by tracing where the existing case fans are plugged in.

This also raises a question in my mind about the 4-pin splitter device you have. You say it is used in the case to connect LED's. So it may NOT actually be suitable for fan power - I don't know.

I also wonder where you plan to mount the new 160 mm fan in the case so it can cool something? That case seems to be completely full with no obvious location for adding a large fan.

If I understand this correctly, the PSU (power supply unit) that is usually a module inside a desktop machine is not that way at all in this machine. It appears the power supply is a completely separate external module that connects to the computer via a cable. Is that right? In that case, I doubt there are any standard 4-pin Molex PSU output connectors to power anything.

 

[ghost101]

Yes, that is correct the PSU is external which is how Asus was able to create this gaming machine in a smaller form. The vents in this machine are horrible, so I went ahead and cut out a spot for a 120mm sized fan in front of where the GPU is located, giving it some much needed air when gaming. Even with no fan, my GPU went from 76 F to 52 F and that is great, but i want to place the 120mm (or larger) fan in the slot I cut out for additional exhaust. I put a mesh covering over the slot I cut open for now as well, but over all the goal was to install a fan in this spot.

 

[Paperdoc]

Hmmm! So you can mount the new fan, but you need access to a 12 VDC supply. There do not appear to be any standard 4-pin Molex connectors inside your case, I presume. They are about ¾" wide with four holes in a straight line, and are commonly used for optical drives (also for old IDE HDD's you do not have). But your machine may have an optical unit with a SATA power connector on it - that is a PC card edge connector with 15 contacts in a straight line, same as the wide connector on your HDD.

Best idea I have is to trace the wires from your existing fans back to where they plug into the mobo. If that is a standard 3-pin or 4-pin fan post, you could use a Y-splitter to convert one port to two, and plug your new fan into that. If it happens to be a 4-pin mobo fan port, your 3-pin fan will always run at full speed. That may be OK for you - you seem to want lots of additional cooling anyway.

The only other option might be to splice into a known 12 VDC supply, like the appropriate wires leading into a SATA power connector. This is getting into cutting and splicing, not merely using adapters that plug in. If you do this, note common color coding: Red is +, Black is -. Look up the pinout details of connectors on the web. For SATA power connectors particularly, splicing into a wire might be better than trying to connect to contacts in the connector. I read that those connectors use THREE contacts for +12 VDC because 1 contact can't support the currents used by many devices.

On your new fan's case there should be two arrows: one points parallel to the fan shaft and indicates direction of air flow when the fan is wired correctly; the other is around the case and shows direction of fan blade turning. If you happen to reverse the fan's power connections by mistake, no big damage - the fan simply will turn backwards. So un-reverse the connections.