[SOLVED] LED lights on fan don't work ?

[dimitris_37]

Hello to everyone,i have a strange issue in new pc ,i connect 3 pin led fan to 4 pin motherboard
fan spin but no light ,works only on miles but is noisy...

ty

 

[Aeacus]

What you have connected, is fan power cable. (A)RGB LED fans, most of them, have 2nd wire to power and control the LEDs. So, look if you have 2nd wire on your fan.

Btw, fan make and model is?

 

[dimitris_37]

What you have connected, is fan power cable. (A)RGB LED fans, most of them, have 2nd wire to power and control the LEDs. So, look if you have 2nd wire on your fan.

Btw, fan make and model is?

Deepcool RF 120B no pwm

 

[Aeacus]

Gave it a look and as far as i can tell, LED should light up. If it doesn't, you have defective fan and you can make a warranty claim on it, to replace it.

 

[dimitris_37]

Gave it a look and as far as i can tell, LED should light up. If it doesn't, you have defective fan and you can make a warranty claim on it, to

 

[dimitris_37]

When Imconnect to molex works just fine but full speed..

 

[Paperdoc]

NO. This is an older fan design called a LED Fan. It has only ONE colour of LED in the frame and there is NO adjustment of the lights. The LED's are simply connected in parallel with the fan motor so they come on whenever the fan motor is running. There is only ONE cable that goes to a fan header. As OP says, this is an older 3-pin Voltage Control fan motor design. With that system the motor speed is controlled by the Voltage supplied to it by the header, and that means that the BRIGHTNESS of the lights will be reduced when the motor is running at low speed.

OP, do NOT connect BOTH the 3-pin small fan connector AND the 4-pin Molex larger connector at the same time. You must use only ONE of these options. Disconnect the Molex and use only the mobo fan header, and ensure that the header is configured to use the older Voltage Control Mode (aka DC Mode), not PWM Mode. When that is set, if the lights still do no come on even when the fan motor is running fast, then the LED's in the fan have failed.

 

[dimitris_37]

NO. This is an older fan design called a LED Fan. It has only ONE colour of LED in the frame and there is NO adjustment of the lights. The LED's are simply connected in parallel with the fan motor so they come on whenever the fan motor is running. There is only ONE cable that goes to a fan header. As OP says, this is an older 3-pin Voltage Control fan motor design. With that system the motor speed is controlled by the Voltage supplied to it by the header, and that means that the BRIGHTNESS of the lights will be reduced when the motor is running at low speed.

OP, do NOT connect BOTH the 3-pin small fan connector AND the 4-pin Molex larger connector at the same time. You must use only ONE of these options. Disconnect the Molex and use only the mobo fan header, and ensure that the header is configured to use the older Voltage Control Mode (aka DC Mode), not PWM Mode. When that is set, if the lights still do no come on even when the fan motor is running fast, then the LED's in the fan have failed.

Thanks for reply so i need 4 pin case fan or adaptor 3pin to 4 pin?

 

[dimitris_37]

Thanks for reply so i need 4 pin case fan or adaptor 3pin to 4 pin?

i was use only one connector 3 pin,only checked with molex ty

 

[Paperdoc]

You do not need anything else. A 3-pin fan CAN be plugged into a 3-pin OR a 4-pin mobo fan header and it WILL work. The 4-pin fan design has NOTHING to do with lights. The 4th pin added is only for passing to the fan a speed control signal called PWM for a different control system. The speed of YOUR 3-pin fan is controlled by the Voltage supplied to it from header Pin #2.

However, if that fan always runs fast and never slows down, there is a configuration item you should check. MOST 4-pin fan headers on a mobo today can ne set to use either the older Voltage Control Mode (aka DC Mode) of control signals, OR the newer PWM signals. You should go into BIOS Setup and find the header where that fan is plugged in. Look for an item where you can choose between Voltage or DC Mode, PWM Mode, and maybe Automatic Detect Mode. Set this for Voltage (or DC) Mode for your 3-pin fan. Then ensure that the PROFOLE item is set to Standard or Normal, and not Manual or Quiet or Turbo. After making changes, use Esc back to the Main Menu, then F10 to get to the Exit Menu. There choose to SAVE and EXIT to save your settings and reboot.

NO other connection or adapter is required for the lights to work in your fan. If the fan it turning at a normal speed, the lights should be on. If they are not, then the lights are faulty. That is, of course, assuming the fan IS one with lights in it. The Deepcool Model RF120B you cited DOES had BLUE lights in its frame.

 

[dimitris_37]

Thanks for reply ,i enable voltage control in motherboard fan spin but still no light....
Can put maybe an adapter 3 to 4 pin and works?
Like this https://www.skroutz.gr/s/25766142/Ekwb-4-Pin-pwm-3-x-4-Pin-pwm-Cable-0-10m-Μαύρο-4-PIN.html
Ty

 

[Paperdoc]

No. All that adapter can do is the SAME as plugging the fan's 3-hole female connector into the mobo's 4-pin header. When you do that, the 4th pin of the header is NOT used. That pin ONLY sends to a 4-pin fan the PWM motor speed control signal. It is NOT used for fan lights! The 3-pin fan can not use that signal for anything.

If your motor turns at normal speeds but the lights do not work, then the lights are faulty. Either replace the fan, or ignore the problem.

 

[Paperdoc]

Thanks for Best Solution, and good luck.