4 pin GPU fan on a computer with no such connector

[Djuka]

I bought a new fan for GPU and it has 4 pin mini connector. Problem is I made a mistake. My graphics card has 3 pin connector only and I don't have any 4 pin mini connector on my motherboard. I tried plugging it on 3 pin connector (without control cable), but it didn't work. How can I overcome this? What am I to do?

 

[Robert Cook]

try shifting it on the three pin, three pin and four pin tend to work anyway.

- - -
1 2 3

- - - -
1 2 3 4
Or

- - -
1 2 3
- - - -
1 2 3 4


also try flipping it around
- - -
1 2 3
- - - -
4 3 2 1


As you can see there are lots of ways for it to work

 

[Paperdoc]

I'm not sure what you mean when you say, "(without control cable)". For starters, does the fan you bought have a common 4-pin connector on the end of its wires, exactly like those on most case ventilation fans? If it does, those should ALWAYS fit onto any standard mobo 3-pin fan port connector. And no, there are NOT "lots of ways for it to work". There is only one way it fits. The mobo male connector had a plastic tongue sticking up by the 3 pins, and the fan's connector has a slot on its side so you can only plug it in one way. Any standard 4-pin fan CAN work properly when connected to a standard 3-pin fan port. That includes the ability of the mobo's automatic fan speed control to manage that fan's speed.

Now, IF that is the connector type on your new fan, and IF your graphics card has a standard 3-pin fan port on it, the same should apply: you should be able to plug the new fan into the graphics card's connector and it will work under automatic control.

The fact that you say it cannot work makes me think that there is something odd about the connectors here. Look carefully at: (a) the connector on the end of the wires from your OLD graphics card's fan: (b) the 4-pin connector on the new fan; and, (c) the 3-pin fan ports on your mobo. They should all look to be about the same size and should fit together. The only difference should be that the new 4-pin connector is just a bit wider with an extra hole. If that is NOT what you see, tell us what actually is there. Is one type of connector larger, or a different shape? In each case, how many wires come from the fan motor to its connector? What is the "control cable" you mentioned?

 

[Djuka]

I'm not sure what you mean when you say, "(without control cable)". For starters, does the fan you bought have a common 4-pin connector on the end of its wires, exactly like those on most case ventilation fans? If it does, those should ALWAYS fit onto any standard mobo 3-pin fan port connector. And no, there are NOT "lots of ways for it to work". There is only one way it fits. The mobo male connector had a plastic tongue sticking up by the 3 pins, and the fan's connector has a slot on its side so you can only plug it in one way. Any standard 4-pin fan CAN work properly when connected to a standard 3-pin fan port. That includes the ability of the mobo's automatic fan speed control to manage that fan's speed.

Now, IF that is the connector type on your new fan, and IF your graphics card has a standard 3-pin fan port on it, the same should apply: you should be able to plug the new fan into the graphics card's connector and it will work under automatic control.

The fact that you say it cannot work makes me think that there is something odd about the connectors here. Look carefully at: (a) the connector on the end of the wires from your OLD graphics card's fan: (b) the 4-pin connector on the new fan; and, (c) the 3-pin fan ports on your mobo. They should all look to be about the same size and should fit together. The only difference should be that the new 4-pin connector is just a bit wider with an extra hole. If that is NOT what you see, tell us what actually is there. Is one type of connector larger, or a different shape? In each case, how many wires come from the fan motor to its connector? What is the "control cable" you mentioned?

At the end is the link to photos of all connectors I mentioned above. I understand what you are talking about and I read about it before and tried it out, but this didn't have any success. Maybe the fan is broken?

http://www.mediafire.com/folder/ghdfv1ziqwz1f

 

[Paperdoc]

In your photo collection, the ones for 3-pin and 4-pin seem to be the same. They both appear to show a "standard" 4-pin fan connector for a case ventilation fan, with the common colour coding: Pin #1 (Black) is Ground; Pin #2 (Yellow) is +12 VDC; Pin #3 (Green) is the speed pulse signal (2 pulses per revolution) generated in the fan motor and sent back to the fan port on this line; and Pin #4 (Blue) is the PWM signal from the port to the little controller chip inside the motor case. Thus I conclude the new fan you bought is a "standard" 4-pin (or PWM) fan commonly used for case ventilation.

Now, the 3-pin fan port you show on your graphics card is NOT what is commonly used for a 3-pin case ventilation fan port on a mobo. The main difference is that it does not have the vertical tongue sticking up beside its three pins. Thus, it is not obvious how to plug the fan into this connector. Are you sure this connector on the graphics card is intended to plug in a fan for that card? Was the old cooling fan on that card plugged in there?

There is one suggestion I can offer without more details. The common 3-pin case ventilation fan has different colour coding on its wires, BUT the connection pins are the same for Pins 1 to 3. It is just missing Pin #4. So BOTH 3-pin and 4-pin fans have a Black wire on Pin #1 and that is Ground. On a 3-pin fan, the +VDC supply on Pin #2 is Red, whereas your 4-pin fan has a Yellow wire there; however, in BOTH cases this is the + VDC supply for the fan. Similarly, Pin #3 in BOTH cases is the speed signal - it's Yellow on a 3-pin fan, and Green on your 4-pin fan.

So, if you can figure out which end on the 3-pin connector on your graphics card in Pin #1, we can proceed. If you can remember how your card's old fan was plugged in there, it is a good guess that the BLACK wire was on Pin #1, and so the BLACK wire of your new fan should go to that end of the connector. If the spacing of the connector holes on your fan matches the spacing of the pins on the card's fan port, you will be able to fit the connector on. When you do, the 4th hole of the fan's connector will not fit onto anything, and that is OK. So try fitting it that way.

IF the fan port on your graphics card operates just like a mobo 3-pin fan port, this can work. The backwards compatibility design of 4-pin fans means that they CAN operate properly and have their speed controlled by a 3-pin port. When connected this way, the 4-pin fan receives no PWM signal to use, but its voltage supply on Pin #2 is not a constant 12 VDC - it is reduced by the fan port when necessary to change the fan's speed.