[SOLVED] Case Fan Help

[ndf8g3]

I plugged my system fans into where it's labeled sysfans on the motherboard. I just can't figure out where to place the larger piece of the fan wire. It looks like this:

Amazon.com: J&D [2-Pack 4 Pin Molex to 3X PWM Fan Splitter Cable - 12 inch: Computers & Accessories

Amazon.com: J&D [2-Pack 4 Pin Molex to 3X PWM Fan Splitter Cable - 12 inch: Computers & Accessories

www.amazon.com

The one all the way on the right. Thank you in advance.

 

[ndf8g3]

I have an Aorus Pro Wifi Z390. The fans I have are here:

https://www.amazon.com/Computer-Adv...re+case+fans&qid=1568673172&s=gateway&sr=8-12

 

[Paperdoc]

When you connect the smaller standard fan connectors to your mobo headers, do NOT connect the larger ones anywhere! Those are called 4-pin Molex male connectors. They are designed to connect to a PSU output for power IF you cannot use mobo headers. But you must NEVER connect BOTH connectors from one fan to the two different power sources. Doing that can force power from the PSU back into the mobo headers and may damage your mobo.

 

[ndf8g3]

When you connect the smaller standard fan connectors to your mobo headers, do NOT connect the larger ones anywhere! Those are called 4-pin Molex male connectors. They are designed to connect to a PSU output for power IF you cannot use mobo headers. But you must NEVER connect BOTH connectors from one fan to the two different power sources. Doing that can force power from the PSU back into the mobo headers and may damage your mobo.

Thank you Paperdoc, I just can't seem to get the fans on. Do you know of any reason why they'd not be on when I have the 3 pin connectors in the mobo headers? They're brand new, don't think they'd be defective.

 

[Paperdoc]

I agree, they should be working. Those are fans called "LED fans". That is, they include (Blue) LED's mounted in the fan frame and connected to the same power being fed to the fan motor. Thus they consume a bit more power than a plain fan, but not enough to cause this problem IF you have each fan plugged into its own mobo fan header. HOWEVER, if you are using a Splitter to connect three (or more) of them to ONE header, that would cause this problem. Note also that the lights on a fan may get dim if the fan is sent signals to run quite slowly. Beyond that, check these items.

1. The female connector on the end of each fan's wires has 3 holes and two ridges down one side. Those ridges fit around a plastic tongue sticking up beside the first three pins of the the four-pin mobo header. That way there's only one way to connect. When it is done right, the fourth pin of the header (outside the two ridges) is not being used.
2. I suggest using SYS_FAN1 through 4 headers. Although the ...5 and ...6 ones ought to work just as well, they are also intended for possible use with pumps.
3. Go into BIOS Setup and see your manual p. 32. For EACH of the mobo headers you are using for these case fans, review and adjust the configuration as follows.

(a) Fan Speed Control to Normal
(b) Fan Control Use Temperature to the motherboard sensor, not the CPU sensor
(c) Fan / Pump Control Mode to Voltage, not Auto or PWM
(d) Fan / Pump Stop Disabled
(e) Fan / Pump Fail Warning Enabled
When you have all of them set, remember to back out to the main screen and use the F10 key to reach the Exit menu. There choose the SAVE and EXIT option to save your settings and reboot.

If all of those fans still fail to work, and especially if none of them show any blue lights, then they may all be faulty. These fans work on a power supply of 12 VDC max. So you could rig a temporary feed of such power using small wires to test each. A handy 12 VDC source for many is a plain auto battery - and this use will NOT drain that battery and harm it. To make the connections, a car battery has one larger post that is the +12 VDC post, and the smaller on is - and connected to the car frame Ground. On your fans, the easiest connection points are in the wider Molex connectors. The have space for 4 pins, but only have 2 pins mounted. Of those, the one nearest the edge is the + terminal, and the one nearer the middle is the -. So just connect a small wire from battery + (larger one) to the Molex pin closer to the EDGE, and another from - to -. The fan should start up and run full speed, and the lights should come on fully. If they don't, the fan is faulty. If the DO work this way but NOT when connected to your mobo headers, there may be a mobo fault.

 

[ndf8g3]

I changed all those settings, except I wasn't sure what the motherboard sensor was so I set it to the pcie16. The 3 pins went into sys_fan2 & 3 and were fitted correctly with the 1 pin sticking out, right onto the plastic tongue. I couldn't install my motherboard drivers, could this be it? I don't have an optical drive. Could it also be the open chassis? One of the fans works so I doubt it. I have the case open for ease of access until it is complete. I wonder if these fans only work under high temp, but then again one of them from the same pack is running at all times.

 

[Paperdoc]

Go back into BIOS Setup for EACH of your fan headers and check items (c) and (d) from my list above. If (c) Control Mode is set to PWM, the fan will always run full speed. In fact, that is one way to test your fans. For each of those fans, temporarily set its fan header to PWM Mode, then back out and SAVE and EXIT. This should feed all of those fans with the full 12 VDC and they all should start and never slow down. If that works, then you know the fans are OK and a different item will need adjustment. So report back here whether they all run full speed that way, or do nothing. Then go back into BIOS Setup and change them all the DC Mode, SAVE and EXIT.

As I said in (d), the fan must NOT be set to Stopped.

Regarding which temp sensor to use, post back here exactly what choices you do have, since the manual does not show that. Normally the PCIe16 is not the right one.

 

[ndf8g3]

The temp sensors are as follows, system 1, pch, cpu, pciex16, vrm mos, and ec_temp1. Further down to other sysfans it is system 2 and ec_temp2. The ec temps are for thermistor cables that I have no idea where to put. One side plugs right into the mobo and there is a small pin on the other that goes nowhere.

The fans have always been on stop disabled. The fans are doing nothing while set in PWM with all other corresponding settings. Whats the DC mode?

 

[Paperdoc]

OK, so among those six sensor choices, only the ones called system_1 and system_2 are for the general mobo, and suitable for case ventilation fan control. There is no information in the manual for which of those two should be used for case vent fans, so just pick one. The other four, including the CPU one, are all for specific components. They are useful only of you know where that components is and you have chosen to mount a fan aimed directly at that so you can concentrate some cooling there. Generally this is NOT needed.

The mobo comes with two optional thermistors, which are temperature sensors you can mount where you think you need to monitor a temperature. Each will have a 2-pin connector to plug into a mobo port, and the other end will just be a thin little metal tip. That is where the sensor is, and that's what you mount if you want to. Although the mobo will allow you to use these for controlling a fan, I do not advise that. First, it can be very difficult to mount a sensor so that it actually measures a component temperature you want, and to ensure that it is so securely mounted that it stays there and gives reliable info. Secondly, in almost all cases you have NO idea what the "correct" temperature for that spot is, so how can you decide to automate cooling there? However, you might want to connect those sensors and display something like the intake (room air) temperature, just for interest, without actually using that reading for any control purpose.

The fan headers you are using for the fans must NOT be set to Disabled / Stopped. THAT is why the fans are stopped! Change those to Enabled.

Sorry about the "DC Mode". That is another term some mobos use for the Voltage Control Mode, and that's how your mobo labels it. Since you have 3-pin fans, if the header each is connected to is configured to the new PWM Mode, they will run, but only at full speed all the time with no control. So set them instead to Voltage Mode, and the header can control their speeds.

 

[ndf8g3]

Thanks Paperdoc, I appreciate all your help. The fans still won't work, maybe they're defective. Think I'll have them looked at.

 

[Paperdoc]

You're welcome. Let us know what you find out.
Thanks for Best Answer.

 

[ndf8g3]

Paperdoc! They both work fine. With all your recommended settings, I decided I'd mess around with it myself before taking it anywhere. All I did was move one of the fan 3 pins from sysfan3 to 4. The one 3 pin in sysfan2 stayed in the same place, I just unplugged it and plugged it back in. Maybe I didn't have it lined up with the plastic tongue? I thought if it went in it would automatically mean it had to be lined up. Regardless, thank you very much for all your help. You 100% deserved it.