[SOLVED] Cant control case fans with pwm cable distributor

[Omerkoksur]

Hello Everybody,

I can control one pwm case fan from bios menu by using 4 pin socket (my fans are also 4 pin)

When i try below distributor cable, fans only work on max speed (1900) and cant control them from bios. Fan softwares also doesnt work..

Do you have any idea about what could be the problem? If molex is the problem, then what is purpose of this cable to connect on MB then?

What should i do to control my pwm case fans?

Thanks in advance

https://www.hepsiburada.com/akasa-f...Fp3zv-RBlX_eKNuEC0xPrkCIc3Z5gAJ4aAn4KEALw_wcB

 

[Paperdoc]

That is what I call a HUB, not a Splitter, because it gets power for all its fans from the PSU directly via the 4-pin Molex connector. But never mind that, it should work and it is not right now. It IS the correct design for what you are doing.

What MAY be missing is this. To work, that Hub MUST have a PWM signal from Pin #4 of the mobo header that you plug it into. The unit has one of its "arms" with a FEMALE (4 holes) connector that you MUST plug into a mobo 4-pin SYS_FAN or CHA_FAN header. In ADDITION. you need to go into BIOS Setup and find the place to configure that particular fan header. There look for an option to set to to either PWM Mode or Voltage Mode (aka DC Mode). Ensure it is set to PWM, and then be sure to SAVE and EXIT to save your setting and reboot. This will ensure tha the Hub gets a PWM signal it can pass on to all your 4-pin fans so their speed is controlled.

 

[Omerkoksur]

That is what I call a HUB, not a Splitter, because it gets power for all its fans from the PSU directly via the 4-pin Molex connector. But never mind that, it should work and it is not right now. It IS the correct design for what you are doing.

What MAY be missing is this. To work, that Hub MUST have a PWM signal from Pin #4 of the mobo header that you plug it into. The unit has one of its "arms" with a FEMALE (4 holes) connector that you MUST plug into a mobo 4-pin SYS_FAN or CHA_FAN header. In ADDITION. you need to go into BIOS Setup and find the place to configure that particular fan header. There look for an option to set to to either PWM Mode or Voltage Mode (aka DC Mode). Ensure it is set to PWM, and then be sure to SAVE and EXIT to save your setting and reboot. This will ensure tha the Hub gets a PWM signal it can pass on to all your 4-pin fans so their speed is controlled.

Thanks Doc.

Well thats the case, when i directly connect my 4 pin fan to chasis fan 1 i can control it via bios.

But when i use this cable on board, i cant control my 4 pin pwm supported fans...

 

[Paperdoc]

Assuming that you have plugged it in properly, then the unit must have a flaw. The key item to concentrate on is the wiring for Pin #4. That is the line that carries the PWM signal. If your fans work at full speed when this Hub is used and cannot be changed, then the likely cause is that the PWM signal from your mobo is not getting though to the fans.

Look at the female (with 4 holes) connector on the end of one arm. Ylou can see that it has two ridges running down one side, aligned approximately with Pins 1 and 3. Pin (hole) #4 is outside the range of the ridges. Now look at the male output connectors with pins. On the shroud around each you can see the "tongue" that slides between the ridges on a female, and again, Pin #4 is outside of that range of that "tongue". You need some way (voltemeter of something even simpler) to be able to test whether the signal that is suppied to the hole#4 of the female connector gets to anywhere else. From what you say, it never gets to any of the male pins, but check that detail anyway. It MIGHT be that SOME of the fans are getting the signal and running slow, but some are not and are so loud you miss the difference. If there is no connection between hole #4 on the female and all of the #4 pins on the males, then the failed connection is somewhere in the female connector where all the blue wires come together at tha back of hole #4 on the end.

 

[Omerkoksur]

Well i have checked the whole cable with voltemeter, it seems that blue and yellow cables at the male doesnt transmit to the ofther females.. Now i have reordered the cable from different supplier.

What i dont understand is, if yellow and blue cable doesnt get through the fans via females, how am i was able to see its rpm rate at bios and windows =//

 

[Paperdoc]

You have genders of the connectors mixed up. There is ONE female with holes, and FIVE males with pins.

From the photo, the BLUE wire goes to hole #4 on one end of the female connector. The YELLOW goes to hole #3 next to it. Right? Pin #4 is the PWM signal from the mobo and distributed to all connected fans, so it SHOULD connect to ALL 5 males and the female connector. Pin #3, on the other hand, is for the motor speed signal generated at each motor to be fed back to the mobo header. BUT the Hub should only send back ONE fan's speed becasue that's all the header can handle. So there should be continuity between Hole #3 of the female and Pin #3 of only ONE male output. In fact, of the five male connectors, I believe there will be only ONE that actually has a pin in the #3 position.

 

[Omerkoksur]

You have genders of the connectors mixed up. There is ONE female with holes, and FIVE males with pins.

From the photo, the BLUE wire goes to hole #4 on one end of the female connector. The YELLOW goes to hole #3 next to it. Right? Pin #4 is the PWM signal from the mobo and distributed to all connected fans, so it SHOULD connect to ALL 5 males and the female connector. Pin #4, on the other hand, is for the motor speed signal generated at each motor to be fed back to the mobo header. BUT the Hub should only send back ONE fan's speed becasue that's all the header can handle. So there should be continuity between Hole #3 of the female and Pin #3 of only ONE male output. In fact, of the five male connectors, I believe there will be only ONE that actually has a pin in the #3 position.

Few days ago i have received my new cable and it controls all case fans now ! So the problem was in the cable...

Thanks Doc