Case Fan Stopping

[Herc08]

So I just installed two brand NF-A14 fans for front in take. At first I used the spiltter for cable management, but noticed that both fans came with two extendeders (one regular, and one short one for 1200 RPM max). After booting up, it worked fan, then I noticed that the BIOS is not detecting the fans at all. So I figured I had enough routing space to put the fans in its own fan header. Now before hooking up the monitor, I did a boot test, and both fans speed. But after I put the filiter on, one of the fans stops. This is probably after 2-3mins after boot. So the temp is not really being effected. I figured if it was temp-controlled, wouldn't both fans stop since I have the panels off?

This is the front filiter

This is a NZXT S340 case with a Gigabyte mobtherboard, not that I think that matters. Any ideas?

 

[JamesSneed]

I would look in the BIOS and see if that fan header is being thermally controlled. If so the voltage is probably going lower than what is required to start the fan spinning. All fans require a minimum voltage to start spinning. I would play with the fan settings in the bios until the fan at least spins very slowly when you have it opened up like this.

 

[Herc08]

I would look in the BIOS and see if that fan header is being thermally controlled. If so the voltage is probably going lower than what is required to start the fan spinning. All fans require a minimum voltage to start spinning. I would play with the fan settings in the bios until the fan at least spins very slowly when you have it opened up like this.

I tried that too. I downloaded HW Monitor, and the PWN is at 0%.

In the BIOS, I changed it from Normal to Manual. And changed the settings. Also, downloaded SpeedFan, and it connect detect my fans. I just don't see what is wrong.

 

[Herc08]

So this is weird, I have SpeedFan and from what I understand "$A40 on ISA" are your PWN fans, but there is nothing there. I know my motherboard supports this, and I have enabled it in the BIOS. I just cannot understand what is going on.

 

[Herc08]

I've reached out to Noctoa, and this is what they advised:

thank you for contacting Noctua.
I have to agree that it is rather odd that only one of the fans stops, but so far we're not able to rule out a configuration error yet.
Please make sure that only one fan per lna adapter is used as otherwise the adapters may overheat.
You'll get best results when the header is configured to pwm mode. In case the header is voltage controlled, please make sure that mainboard fan control is disabled is when using the lna adapters as using both lna adapters an mainboard fan speed control may lead to spin-up issues.
It won't hurt to try the fans with different headers, if possible without using the included adapters.

I pretty did that already, but I think I may have to remove the LNA adapters. Anyone else has any ideas? I still have the font panel open, and now both fans stop. In the BIOS, I changed it to Manual, but I am not sure if that is making any difference. Can't figure out how to change voltage to give enough power to the fans

 

[Paperdoc]

I consider "Low Noise Adapters" a problem waiting to catch the unwary, and gotcha!

Low Noise Adapters are supposed to be used ONLY with fans that are connected directly to the PSU with its fixed 12 VDC power supply. With that supply a fan can only run full speed. Inserting the LNA into the power wiring reduces the voltage so that the fan can run slower, but still at a fixed setting. If that gives you enough cooling, then it's set up right.

As far as I'm concerned, LNA's have NO PLACE in a system that connects fans to mobo headers and uses automatic control by the mobo. That automatic control (IF it works - see comments below) will manipulate the fan's speed to ensure that a TEMPERATURE target is maintained. In the case of the CPU chip, the temperature sensor is inside the chip. In the case of case ventilation fans, the temperature sensor is built into the mobo. Either way, the mobo system will change the fan's speed to meet the temperature target. There is NO need to use an LNA in such a system. The control will automatically slow down the fan until the temperature is OK, then speed up and slow down as workload changes.

Let's not forget how a "Low Noise Adapter" works. It simply reduces the voltage to the fan so it runs slower and makes less noise BUT that also means it COOLS LESS!. So what happens when you stick that into the leads for a fan under automatic control? Well, the system starts out by setting the fan at some feed voltage it estimates will provide sufficient cooling and watches the temperature sensor. But the fan is blowing less than the control system estimated, so things heat up. Then the automatic controls will speed up the fan, and have to keep on doing that more and more, until the temperature target can be met. Guess what! When there finally IS enough cooling going on, the fan SPEED is the same as if you never used the LNA! And so is the noise generation. It does NOT reduce noise in this system! In fact, what it really does is, when your workload is high and you need more fan blowing, the LNA will not allow enough voltage to get to the fan and you are now under-cooling and over-heating! So you gain NOTHING for reduced noise, and you prevent your system from getting adequate cooling when you work it hard.

There's another effect which may be exactly what OP is seeing. Any fan needs MORE voltage to start up from stopped than it needs to keep running. Normally an automatic system will try to feed full voltage to the fan at start-up for a few seconds, then throttle it back to the proper speed. But if you have added a very low noise adapter to the wiring, the maximum voltage sent out by the mobo header never gets to the fan, and it may not start. Even if it does, if your system cools down from minimal use, the fan will slow down. Now, the mobo system knows that any fan will stall below a certain voltage (about 5 VDC on a Voltage Control Mode system) and it is programmed NOT to go lower than that. BUT if you have an LNA in the wires, the voltage the fan gets is LESS than the minimum the mobo sends out, so it may stall and NOT re-start. Another downside for no gain.

A comment separate from the LNA thing. A mobo-based automatic control system works best if the fan type (3-pin or 4-pin) matches the mobo header type. For mis-matches, this is how it goes. A 3-pin fan plugged into a 4-pin header that really does use PWM Mode will only run at full speed all the time. It cools well, but there's no control of speed. A 4-pin fan plugged into a 3-pin header will run UNDER CONTROL just as a 3-pin fan would because of the backwards compatibility feature of such fan designs. Now here's a tricky "catch". Because of that last 4-pin fan on 3-pin header thing, many mobos now employ what seems like a "universal" header that has 4 pins to make everyone comfortable, but really operates only as a 3-pin header in Voltage Control Mode, with an unused 4th pin. This is OK until you try to use such a header with a 4-pin fan HUB that depends on having a PWM signal on Pin #4 to control its fans. That combination will fail to control any fan.

 

[Herc08]

A comment separate from the LNA thing. A mobo-based automatic control system works best if the fan type (3-pin or 4-pin) matches the mobo header type. For mis-matches, this is how it goes. A 3-pin fan plugged into a 4-pin header that really does use PWM Mode will only run at full speed all the time. It cools well, but there's no control of speed. A 4-pin fan plugged into a 3-pin header will run UNDER CONTROL just as a 3-pin fan would because of the backwards compatibility feature of such fan designs. Now here's a tricky "catch". Because of that last 4-pin fan on 3-pin header thing, many mobos now employ what seems like a "universal" header that has 4 pins to make everyone comfortable, but really operates only as a 3-pin header in Voltage Control Mode, with an unused 4th pin. This is OK until you try to use such a header with a 4-pin fan HUB that depends on having a PWM signal on Pin #4 to control its fans. That combination will fail to control any fan.

Now that is what a post. I should have known LNAs would have some effect. When I am done working, I will remove them, and if that is the case I will pick this as best solution. As far as a "universal" 4-pin header, I believe my motherboard has PWM support. As it is stated in the BIOS and manual. Just would like to control.

What I don't understand is, why would they not mention it in the documentation? I mean it says right there, use LNA to lower fan speeds to 1200 RPM. But it makes sense now. If it is there, it is there to stop the voltage. I've OC'ed my CPU, and ran a stress test, but it is not spinning. And still not being detecting in the BIOS or SpeedFan. So hopefully this will work. Just wanted a quiet PC. I will be leaving that in my Amazon review, being that this is a top-tier fan-making manufacturer.

 

[Paperdoc]

Regarding "PWM Support", virtually ALL mobos use PWM for the CPU_FAN header. Many actually offer you (in BIOS Setup) a choice to set this one header to use either PWM Mode or Voltage Control Mode. So I'm sure the mobo maker is correct in the claim.

The "universal" headers typically show up only on the SYS_FAN or CHA_FAN headers. And technically, although they are not USING PWM Mode to control the fans, they DO support the use of 4-pin PWM Fans.

As I said, I dislike LNA Adapters when used with automatic mobo-based fan controls. However, for those using direct connections to the PSU for their fans, the LNA device is the simple way to reduce fan speed (and noise, and cooling) from full speed. So they do have their place. The other way is using a third-party Fan Controller module to adjust fan voltage supply.

 

[Herc08]

Regarding "PWM Support", virtually ALL mobos use PWM for the CPU_FAN header. Many actually offer you (in BIOS Setup) a choice to set this one header to use either PWM Mode or Voltage Control Mode. So I'm sure the mobo maker is correct in the claim.

The "universal" headers typically show up only on the SYS_FAN or CHA_FAN headers. And technically, although they are not USING PWM Mode to control the fans, they DO support the use of 4-pin PWM Fans.

As I said, I dislike LNA Adapters when used with automatic mobo-based fan controls. However, for those using direct connections to the PSU for their fans, the LNA device is the simple way to reduce fan speed (and noise, and cooling) from full speed. So they do have their place. The other way is using a third-party Fan Controller module to adjust fan voltage supply.

So, my Z170X Gaming 3 mobo has three SYS_FAN headers. Even though it says PWM in the manual and BIOS is this a universal type? Would I need to get a fan controller? I don't have a 5.25" bay to fit it in

 

[Paperdoc]

The three SYS_FAN headers on your mobo are of the "universal" type and actually operate in Voltage Control Mode. Look in your mobo manual on p. 14 where the fan header pins are labelled. The one for CPU_FAN has a fixed +12 VDC on Pin #2, and a Speed Control signal on Pin #4. This header is operating in true PWM Mode. Now compare to the labels for the 3 SYS_FAN headers. Their Pin #2 is "Speed Control" because its voltage is varied to adjust fan speed, while Pin #4 is "VCC", indicating that it is NOT the PWM signal.

You do NOT need a third-party Fan controller, and one of those would NOT give you automatic control of fan speeds based on component temperatures. Your mobo can do the job already, and better. The mobo headers can power and control the speed of both 3-pin and 4-pin fans. The only problem in using them is that they cannot be used with a fan HUB which requires a PWM signal to operate. However, they certainly CAN be used with fan SPLITTERS (the devices that do NOT have any connection directly to the PSU). When using splitters to connect more than one fan to a single header, the limit is that the header can supply up to 1 amp in total. Most common case ventilation fans consume less than 0.2 amps each. The Noctua NF-A14 PWM (4-pin) fan consumes 0.13 amps max, whereas the 3-pin version NF-A14 FLX consumes 0.08 amp max. You can probably find similar specs for the other fans you already have. But the bottom line is you could easily connect three or four such fans to any one of your three SYS_FAN headers with no risk of overloading them. Plus, of course, that would give you automatic mobo control over them all.

In doing this you would NOT use any of those Low Noise Adapters inserted into the fan connections. You should realize a factor in using a Hub or Splitter. The mobo header you plug into can only deal with the speed pulse signal from ONE fan. So a splitter that connects several fans to a header will only connect to it the fan speed signal from ONE fan. If you examine a splitter's male output connector, you will find that all but one of them is missing its Pin #3, so those fan's speed signals are ignored completely.

When you connect fans to headers and want automatic control used, see your mobo manual p. 28 for the options in BIOS Setup. Each SYS_FAN should be set to "Normal" so that the automatic control system can do its job.

These days it's hard to find a 3-pin splitter, but any 4-pin splitter will do the job just as well. Any 3-pin fan merely does not use Pin #4, which in this case does not matter at all. There are lots of splitters around with 2 output arms of various lengths. Here's one with three output arms

http://www.newegg.com/Product/Product.aspx?Item=N82E16812423162&cm_re=Coboc_fan_splitter-_-12-423-162-_-Product

Note this is a SPLITTER with one female connector (plugs into a mobo SYS_FAN header), three male output connectors (two missing their Pin #3), and NO arm to connect to a PSU output.

Regarding how to observe the fans speeds etc, I often see people having difficulty with third-party software tools. It appears many of them require some "tweaking" to work properly with so many different mobos. But all mobos also come with a CD of utilities etc, and one of these will be a utility you can install and run under Windows that gives you a view of lots of things like fan speeds and component temperatures, and even lets you make custom adjustments if you feel the need. To me the BIG advantage of these is that they are provided by the MAKER of your mobo who knows exactly how to read its signals and display them correctly. Look at the contents of your mobo's CD for such a utility. In many cases it is listed as one of the "drivers" you can install in Windows, even though it really is not a device driver at all - it is a software utility. Of course, you can always stop what you're doing and reboot directly into BIOS Setup to get a snapshot of some of these things, but that's not as handy as having a utility display the info on your screen while you're running normal tasks under Windows.