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Fan controllers??? Help, do I need one

Last response: in Systems
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September 14, 2009 2:16:43 AM

Hello,
Very confused.
I have a Antec 900 case. 2 fans in front, 1 on side, 1 on back, and the big one up top.

Now, the top fan and side fan have these little white switches (low, med, high) and hook into the power supply.

The back fan and two front fans do not. There plugs need to go into the fan controller I suppose.

Could I simply replace the other fans with little ones that come with manual switches?
So annoyed with the fan controller. Wires everywhere. You change the speed and it barely does anything.

The 3 fans that appear to need to go into the fan controller for power are Aerokool.

Thanks for any advice.

More about : fan controllers

a b B Homebuilt system
September 14, 2009 11:05:29 AM

I don't own the Antec 900 case, so I'm going to take a guess, since I can't see exactly what your talking about. My guess is the top and side fans are powered by the PSU directly and have their own fan settings (low/med/high). This allows you to adjust their speeds if you like. They are 120mm fans, IIRC, and will move alot of air around at slower speeds than smaller fans. This is a bonus, because you have less fan noise!!

Now the other 3 fans (1 back & 2 in front) should be plugged into your mobo. The mobo usually labels them as Chassis Fan, Power Fan, or something like that. See below:

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a b B Homebuilt system
September 14, 2009 11:06:48 AM

Forgot to mention that the front 2 and the back fans, will be controlled by the mobo (in most cases) so that is why they are plugged into the mobo. This allows the mobo to regulate the voltage to the fans, so it can speed up or slow down the air flow in the case.
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a b B Homebuilt system
September 14, 2009 2:01:57 PM

Important notes on using fan pinout connectors on the mobo.
1. Plug into the CPU_FAN connector ONLY the fan on the CPU cooler. If you have a 4-pin mobo pinout, it will accept both 3- and 4-pin fan connectors - there is only one way to plug each in. The fourth pin (if your mobo has one) is simply for a different way of controlling fan speed and it is not used in 3-pin fans that don't have that feature. The BIOS monitors the CPU fan speed and has certain emergency procedures to follow if it stops - for example, many mobos simply will not start up if the CPU fan does not show speed when given power. The BIOS also controls this fan's speed (unless you set it to run full speed always) based on a temp sensor built into the CPU itself.
2. If you have a PWR_FAN pinout, connect to it ONLY a fan connector coming right out of the PSU. This is a mobo INPUT signal only, allowing the mobo BIOS to monitor the speed of the fan inside the PSU and possibly send out an alarm if it stops. It does not control the PSU fan's speed. If your PSU has no such connector, leave it empty.
3. Most mobos now have two pinouts for case fans, usually labeled SYS_FAN1 and SYS_FAN2. Through these the mobo BIOS can monitor and control the fans connected to them. Of the three fan wires, black is Ground, red is +12 v dc (or less), yellow is fan speed sent back to the mobo. BIOS checks the fan speed for display and alarm functions, and varies the output voltage on the red wire to control fan speed. Within the BIOS you may have some control over speed control details, and you usually have the option of running the fan under control, or at full speed always. Each SYS_FAN connector may be controlled by a different temperature sensor system, or they may both be based on one mobo temp sensor.

If you want to run two case fans from one SYS_FAN pinout it is possible with a little wiring modification. Basically you need to connect together the two black leads and the two red leads to share the same power source, but only ONE yellow fan speed line should be connected to the mobo pinout. With three case fans, OP could do this. Alternatively, OP could connect one of them to one of the independent case fan speed controllers already in use for the top or side fan, or simply plug it directly (via adapter) into a Molex connector to run at full speed all the time.
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September 14, 2009 2:04:18 PM

lunyone said:
Forgot to mention that the front 2 and the back fans, will be controlled by the mobo (in most cases) so that is why they are plugged into the mobo. This allows the mobo to regulate the voltage to the fans, so it can speed up or slow down the air flow in the case.



Thanks,
I do see those connectors.
I guess 2.5 years ago when I did the build I thought it would be control to have the controller, so I got cheaper antec fans without that manual switches.

Now, it's just annoying.
I'll be plugging all directly into M.B. this time.

Thanks
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September 14, 2009 2:08:16 PM

Paperdoc said:
Important notes on using fan pinout connectors on the mobo.
1. Plug into the CPU_FAN connector ONLY the fan on the CPU cooler. If you have a 4-pin mobo pinout, it will accept both 3- and 4-pin fan connectors - there is only one way to plug each in. The fourth pin (if your mobo has one) is simply for a different way of controlling fan speed and it is not used in 3-pin fans that don't have that feature. The BIOS monitors the CPU fan speed and has certain emergency procedures to follow if it stops - for example, many mobos simply will not start up if the CPU fan does not show speed when given power. The BIOS also controls this fan's speed (unless you set it to run full speed always) based on a temp sensor built into the CPU itself.
2. If you have a PWR_FAN pinout, connect to it ONLY a fan connector coming right out of the PSU. This is a mobo INPUT signal only, allowing the mobo BIOS to monitor the speed of the fan inside the PSU and possibly send out an alarm if it stops. It does not control the PSU fan's speed. If your PSU has no such connector, leave it empty.
3. Most mobos now have two pinouts for case fans, usually labeled SYS_FAN1 and SYS_FAN2. Through these the mobo BIOS can monitor and control the fans connected to them. Of the three fan wires, black is Ground, red is +12 v dc (or less), yellow is fan speed sent back to the mobo. BIOS checks the fan speed for display and alarm functions, and varies the output voltage on the red wire to control fan speed. Within the BIOS you may have some control over speed control details, and you usually have the option of running the fan under control, or at full speed always. Each SYS_FAN connector may be controlled by a different temperature sensor system, or they may both be based on one mobo temp sensor.

If you want to run two case fans from one SYS_FAN pinout it is possible with a little wiring modification. Basically you need to connect together the two black leads and the two red leads to share the same power source, but only ONE yellow fan speed line should be connected to the mobo pinout. With three case fans, OP could do this. Alternatively, OP could connect one of them to one of the independent case fan speed controllers already in use for the top or side fan, or simply plug it directly (via adapter) into a Molex connector to run at full speed all the time.




Thanks for details.
I'll check to see what my new M.B. has and go from there. A M4A78t-E
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