Case fan wiring

[bighoo93]

I am just looking over my Antec Three Hundred Two case (http://www.anandtech.com/show/5462/antec-three-hundred-two-stay-cool-budget-enthusiasts), to get comfortable with it and the rest of my components and make some mental notes for the installation. Everything makes sense, although I have a question about the wiring of the two fans that come with the case. There is a 120 mm fan out the rear and a 140 mm fan on top, each with two-speed control from the exterior back of the case. The rear fan has a three-pin female connection for the motherboard. The 140 mm fan has a 4 pin molex connector for the PSU. It also has an adapter that came attached, which repeats the molex connector, but also adds a 3-pin connection like the rear fan has.

My questions are:
- What is the difference between these connections, functionally?
- What does that adapter do? Is it adding to the molex connection, or replacing it with a 3-pin connection?
- Do I or should I use the adapter?

Thanks.

[RickyTick]

The last system I built with the Antec 300 was similar.
I connected both fans directly to the psu using the molex connectors. Then set the fan speed with 2-speed exterior switches. The 3 pin connector is if you want to connect the fan to the motherboard and let it control the fan. iirc

[zburns]

Molex has 'different type plugs'. At least two types show up inside desktop computer cabinets. So I have a couple of questions and I am also providing an answer that I hope fits what you are looking at.


The 140 mm fan has a 4 pin molex connector for the PSU. This molex plug has a width of apx 15/16", I assume. Please confirm.

Next quote:
It also has an adapter that came attached, which repeats the molex connector, but also adds a 3-pin connection like the rear fan has. . . . and the last quote:
The rear fan has a three-pin female connection for the motherboard
Question for the last two quotes is the width dimension of the 3 pin connectors slightly less than 1/2" wide and slightly less than 1/4" thick? I assume those dimensions are correct.
---------------
I have another quote:
There is a 120 mm fan out the rear and a 140 mm fan on top, each with two-speed control from the exterior back of the case.

The fact that there are two, 'two-speed', fan controls on the rear of the case implies that both fans connect up at the rear of the case or onto the motherboard first, then via the motherboard to the inside of the case at the rear.

(I have to look at your on line manual on the case to finish this post -- so back shortly)

[bighoo93]

The last system I built with the Antec 300 was similar.
I connected both fans directly to the psu using the molex connectors. Then set the fan speed with 2-speed exterior switches. The 3 pin connector is if you want to connect the fan to the motherboard and let it control the fan. iirc

One difference, apparently, with the new model is that the rear exhaust fan does not have a 4-pin molex connector, only the 3-pin. The top fan has a molex connector, and also an adapter that came attached that extends the 4-pin molex and also has a 3-pin connector identical to that on the rear-fan. I don't know if I am supposed to connect the 4-pin, the 3-pin or both. I can tell that the 4-pin would go to the PSU and the 3-pin to the motherboard.

[bighoo93]

Molex has 'different type plugs'. At least two types show up inside desktop computer cabinets. So I have a couple of questions and I am also providing an answer that I hope fits what you are looking at.

This molex plug has a width of apx 15/16", I assume. Please confirm.

Next quote: . . . and the last quote:
Question for the last two quotes is the width dimension of the 3 pin connectors slightly less than 1/2" wide and slightly less than 1/4" thick? I assume those dimensions are correct.
---------------
I have another quote:

The fact that there are two, 'two-speed', fan controls on the rear of the case implies that both fans connect up at the rear of the case or onto the motherboard first, then via the motherboard to the inside of the case at the rear.

(I have to look at your on line manual on the case to finish this post -- so back shortly)

Unfortunately I am not at home to confirm with a measurement. I can say that they appear to be "standard" size connections, from what I recall, so if that means anything. I am not at home any more, but am looking for some pictures online to see if that can help describe what I am talking about. Here is a picture I found online, maybe you can figure out something from that:

4 pin connection for top fan (http://www.tweaktown.com/popImg.php?type=content&img=4583_25_antec_three_hundred_two_mid_tower_chas sis_review_full.jpg&title=antec_three_hundred_two_mid_tower_chassis_re view): You can see this dangling down from the top of the picture. Unfortunately it doesn't show the adapter, which is what most of my question is really about.

[RickyTick]

Your link above is broken.

[bighoo93]

Your link above is broken.

Hmm... Works for me. Maybe it is a browser issue? I'm using Firefox.

Here is the review link: http://www.tweaktown.com/reviews/4583/antec_three_hundred_two_mid_tower_chassis_review/index5.html. I was referring to the 10th picture down (I think).

Let's see if this link (http://www.tweaktown.com/popImg.php?type=content&img=4583_25_antec_three_hundred_two_mid_tower_chas sis_review_full.jpg&title=antec_three_hundred_two_mid_tower_chassis_re view) works.

[RickyTick]

Your new links work fine.

This is what I'm seeing with the first link. fwiw
2

[zburns]

Here is a link to the online Antec Manual for the 'Three Hundred Two Case' . http://www.antec.com/pdf/manuals/ThreeHundredTwo_Manual_EN.pdf

On page 20 of the manual are the specs for the 120 mm rear fan and 140 mm top fan. The name of the fan is 'Two Cool' because it has two speeds only, so the speed switch only has two positions. The combination of the 120 mm fan, including the 'two speed switch', has a three pin 'small width' plug slightly less than 1/2" in width that is meant to be plugged into the mobo.

Likewise on page 20 are the specs for the '140 mm Two Cool Fan'. Two wires, red and black, leave the fan and are terminated in a 'normal' molex connector for connection to a 'normal' molex psu connector. The 140 mm fan has a single wire going to a separate two way speed switch.

Provided the three pin plug on the adapter cable is identical to the three pin plug at the end of the cable leaving the 120 mm fan, then this three pin plug on the adapter cable is meant for the mobo (it is an optional choice) (140 mm fan).
----------------------------

Note: Antec also has Tri Cool Fans but according to the manual (link above), only 'Two Cool' Fans are used in the Antec 302 case.

At the moment I see no need to use the adapter cable since there is a two speed switch on the back of the case for EACH of the two pre-wired case fans, 120 mm and 140 mm.

[bighoo93]

Here is a link to the online Antec Manual for the 'Three Hundred Two Case' . http://www.antec.com/pdf/manuals/ThreeHundredTwo_Manual_EN.pdf

Provided the three pin plug on the adapter cable is identical to the three pin plug at the end of the cable leaving the 120 mm fan, then this three pin plug on the adapter cable is meant for the mobo (it is an optional choice) (140 mm fan).

Is the optional connection to the motherboard in addition to the connection to the PSU, or instead of it? Either way, is there any benefit to connecting it to the motherboard?

[zburns]

The last system I built with the Antec 300 was similar.
I connected both fans directly to the psu using the molex connectors. Then set the fan speed with 2-speed exterior switches. The 3 pin connector is if you want to connect the fan to the motherboard and let it control the fan. iirc

The above quote is Ricky's post (2nd one above at the top). In effect he is saying there is no reason to connect either one to the mobo. I do not see any reason to connect either fan to the mobo; however it bothers me that Antec is furnishing a plug for the rear fan that only will go on the mobo. Antec, in effect, is saying effectively, 'it is important to hook this fan (the rear one) to the mobo. You have 'two speed, speed switches on both fans'. No practical reason for the mobo to control the speed. Directly wired to the PSU is a more direct, more 'fail safe' and simpler way to control the fan supply.

My rear case fan (Antec Sonata case) is connected to the PSU via a molex type plug to a PSU molex plug. There should be a reason for this; I will look for it some more and post back to you asap! Antec should have a reason! Sometime tomorrow latest.

[RickyTick]

The benefit to connecting the fan to the motherboard is that you let software handle fan operations. I prefer to connect directly to the psu and just select the fan speed that I want.

[RickyTick]

The fourth pin is likely to provide power to a LED if the fan has one. Otherwise, the fourth pin does nothing.

[zburns]

Here is an Intel page that speaks of 3 pin and 4 pin fan connectors. The original date is 2004 (I initially trashed it with this date). It also has a very long list of Intel mobos, the last of list having Z68 chipsets. And the 'last modified' dates are 2004 thru 2012. So it is indeed authentic and would appear to be good information. Fan control only exists with 4 pin motherboard headers and a mating 4 pin female plug is what I take away from the two page article. It has diagrams -- all simple stuff, worth reading and useful as future reference.

So when does one use the mobo to control fans. My Sonata case uses a rear panel exit fan, same speed all the time. The Antec 300 II case can have a 'lot' of fans. I can see my dilemma if I had both a case like the Antec 300II and 4,5 or 6 fans all running at the same time. Obviously when searching the net, one topic at a time, even multiple screens open at the same time, no games being played, then low fan use is called for. With high energy games being played, two way or 3 way SLI going on, then all fans may be needed.

My comment, initially simply indicated I have no need for fan control with just one fan. But if I maxed out all the fans that could go in the 300 II case, I do not know how I control that 'fan scenario' in a logical, makes sense way. Point is that I think I would try the 'mobo fan control' method, at least to make a comparison.

Here is the link: http://www.intel.com/support/motherboards/desktop/sb/cs-012074.htm

[bighoo93]

Here is an Intel page that speaks of 3 pin and 4 pin fan connectors. The original date is 2004 (I initially trashed it with this date). It also has a very long list of Intel mobos, the last of list having Z68 chipsets. And the copyright dates are 2004 thru 2012 (last updated). So it is indeed authentic and would appear to be good information. Fan control only exists with 4 pin motherboard headers and a mating 4 pin female plug is what I take away from the two page article. It has diagrams -- all simple stuff, worth reading and useful as future reference.

Here is the link: http://www.intel.com/support/motherboards/desktop/sb/cs-012074.htm

Thanks. I appreciate the research you guys have done and the information you have provided. The 3-pin connection on that Intel page appears to be the 3-pin connection on the rear fan and the adapter. But the 4-pin connection is definitely not the same one they are talking about. It is not just an additional pin slot (it is a female connection) on the same 3-pin connection. The 4-pin is an entirely different connection type. It is also a male connection, unlike the 3-pin connection.

Anyway, I think I will just experiment. It sounds like you have settled for me that there is no particular reason to try to connect the fan to the motherboard if there is another option, so I will probably just remove the adapter from the top fan, make those connections, and see how it goes.

[zburns]

Sorry to sound so confusing about the Molex plugs. The 4 pin I refer too is identical to the 3 pin except for the width; the 4 pin is one pin 'wider'. This entire line of 'small' plugs is the Molex type KK series and this entire family of plugs ranges in pin sizes from one pin to forty pins, black or white, plugs, pc board mounted and more!

You are referring to larger Molex male or female 4 pin plugs that are on the ends of the cables from the PSU -- the whole 'build it yourself computer industry' refers to Molex in the 'context' of the PSU plugs.

Side note. In addition, there are a number of competitors world wide that make identical plugs to the Molex. But Molex came first, and the name has evolved over the years to the point that almost everyone refers to these type plugs as Molex regardless of the actual manufacturer.

[ARchamps]

Molex is pretty standard. Most fans have the 3 pin connection. If you don't have enough space on your MB, most fans usually have the adapter to molex to connect to the PSU. When connected to the PSU, the fan will usually run at full speed (unless it has a switch or fan control knob). Alternatively, you can buy a Fan Control module that fits into the drive bay. Instead of going through the MB, you can connect to the fan controller and PSU for controls. Here is an example (http://www.newegg.com/Product/Product.aspx?Item=N82E16811998077).

Personally, I have most of my fans hooked up to my MB and controlled through the ASUS software based on a profile. If temp in my case goes up, the speed will increase etc. I also have a large intake connected to the PSU, which has a fan control knob.

Hope that helps!

[bighoo93]

So I am starting on assembly this morning, and related to this issue of the case fans, I've found a more significant problem. The connection from the rear fan doesn't reach the motherboard. This is a serious design flaw in the case, IMO (since the fan ships with the case). It is conceivable that the mobo connector could be in a position that the fan connector could have reached, but really it is already pretty close and there is no reason for this sort of screw-up. Really, I find it stunning, because for every other connection in the entire case, there is so much excess wiring that cable management is the issue (not a challenge, this case is quite good for that with a couple of exceptions). But the fan cable is very short and there is just nothing I can do to get it connected. I assume there are extensions sold for this sort of thing. Of course, I am sure that since I only need about two inches (or less), I will end up with a huge extension and have excess cable to deal with again. Frustrating.

[zburns]

You can call Antec tech support. They should be able to send an extension that can be wired in or they might have a 'plug in extension which is not a good idea' unless you can keep it from coming apart. (Best to avoid the plug altogether)

Best solution is to splice in 3 or 4 (or more depending on routing) inch extension, solder both ends of splice, cover with heat shrink tubing. Best solution, done properly, repair is good as brand new, 'as if never happened'.

You can do it. A hobbyist can do it. A TV/electronics repair shop can do it and they would most likely have the materials on hand to do it; material cost is extremely small; under a dollar. For example, 3 - 7" pieces of # 22 wire and a 1" to 1 1/2" length of rosin core solder-- hardly a $ 1.00 worth! If you buy the materials at Radio Shack incl a solder iron, your cost then about $ 20 to 25. A shop might just give you the materials (no solder iron tho), no charge, as PR move! They might loan you a solder iron.

If you want to do it, I can give you a check list on procedure and parts.

[bighoo93]

You can call Antec tech support. They should be able to send an extension that can be wired in or they might have a 'plug in extension which is not a good idea' unless you can keep it from coming apart. (Best to avoid the plug altogether)

Best solution is to splice in 3 or 4 (or more depending on routing) inch extension, solder both ends of splice, cover with heat shrink tubing. Best solution, done properly, repair is good as brand new, 'as if never happened'.

You can do it. A hobbyist can do it. A TV/electronics repair shop can do it and they would most likely have the materials on hand to do it; material cost is extremely small; under a dollar. For example, 3 - 7" pieces of # 22 wire and a 1" to 1 1/2" length of rosin core solder-- hardly a $ 1.00 worth! If you buy the materials at Radio Shack incl a solder iron, your cost then about $ 20 to 25. A shop might just give you the materials (no solder iron tho), no charge, as PR move! They might loan you a solder iron.

If you want to do it, I can give you a check list on procedure and parts.

Thanks. But I figured out something even simpler, and now I feel kind of silly for even having posted the issue here. I unscrewed the fan, rotated it 90 degrees, re-installed it into the case, and now the wire reaches perfectly. Duh...

Antec ought to pre-attach the fan in an orientation that allows more flexibility, but I jumped the gun on calling them out on a design flaw.

[zburns]

now the wire reaches perfectly.

I assume it follows the contour of the cabinet. Ie: does not stand out in the middle of open space inside the cabinet where it can be 'hit' and maybe pull loose from the mobo!

[bighoo93]

I assume it follows the contour of the cabinet. Ie: does not stand out in the middle of open space inside the cabinet where it can be 'hit' and maybe pull loose from the mobo!

Yes, it is actually quite elegant now. It runs along the fan casing (inside the lip of the outside of the fan case) and then drops right down into the SYSFAN2 slot. Of course it is "in the open" when it drops to the mobo, but I don't see any way that can be avoided for any connection. Also, if it gets "hit" by something flying around in open space like that, I've got bigger problems than the fan wire coming out! :cool:

[bighoo93]

Just to close this thread out, Antec did respond to my email about the issue with the fan (which I had sent before I found my own solution). They said that the fan connector is the standard length, implying that it shouldn't be a problem. They said they don't sell connectors but I could pick one up at Amazon for $2. Well, it is a problem, and the Anandtech reviewer had the same issue (http://www.anandtech.com/show/5462/antec-three-hundred-two-stay-cool-budget-enthusiasts/3) so it isn't just dumb ol' me. :p However, rotating the fan 90 degrees works so well that I just think they are just shipping it with the fan in the wrong orientation. No big deal in the end. I think it is an outstanding case, and I plan to give a review of it and a few of the other components that I used for my latest build.

[zburns]

If you would, tell me whether the two speed switches have just one wire going to each, or is there a second wire to each switch. In the photo I saw (which was a good picture) on Tweaktown, it only looked like each switch had just one wire. If this is the case, that would mean they are using 'case ground' as a 'return electrical circuit' and I would like to look further into that kind of 'situation'.