[SOLVED] 3 pin fan won’t latch onto 4 pin header on mobo

McBleno

Prominent
Dec 3, 2021
7
0
510
I have a budget build I did for my son. Case came with fans so I basically stuck with those. One fan went bad recently so I replaced not knowing the difference between pnw (?) and DC I got a 3 pin and I read online that it should just latch on the 4 pin header on my motherboard Gigabyte b450M but it doesn’t seem to latch

the fan does work but the wire is seated in such a way that a tug lightly will displace it and I’d need to pop it back in. Is this normal? The other fan did not have any kind latch basically the same design but 4 pin and it seems to latch on
 
Solution
I've never had the slightest issue attaching a 3 pin fan to a 4 pin header.

I'd have to assume the connector is just a bit poorly made. I'd probably continue to use it if you don't have another and monitor temps......it may have little real world effect.
"Latch".......Not sure what that means. Fans generally are just a press fit onto the pins, without a separate latching mechanism. You need to make sure the plug is in fact sliding down onto the pins. That can be tough to see.

Do you have better luck if you rotate the fan cable 180 degrees......or if you use some other random fan on the same fan header?

You may just be a victim of poor quality control by the fan maker. Hard to say without actually looking at it.
 

McBleno

Prominent
Dec 3, 2021
7
0
510
"Latch".......Not sure what that means. Fans generally are just a press fit onto the pins, without a separate latching mechanism. You need to make sure the plug is in fact sliding down onto the pins. That can be tough to see.

Do you have better luck if you rotate the fan cable 180 degrees......or if you use some other random fan on the same fan header?

You may just be a victim of poor quality control by the fan maker. Hard to say without actually looking at it.
Sorry by “latching” on I mean it doesn’t seem to want to stay in place and is loose but once it is in loosely the fan does work which I guess must means the pins are connected. It can easily be disconnected by the lightest movement. Other fans like the one that was previously removed does stay in place correctly they seem secure and require force to disconnect, and I tried one of the other case fans in this header and this fan in that header and the old case fans seem to stay in place while this new fan does not in both instances

I’m not sure if it’s a 3 header going into a 4 header issue or just bad quality
 
I've never had the slightest issue attaching a 3 pin fan to a 4 pin header.

I'd have to assume the connector is just a bit poorly made. I'd probably continue to use it if you don't have another and monitor temps......it may have little real world effect.
 
Solution

Karadjgne

Titan
Ambassador
It can depend on the actual connector, age of the fan. It used to be (years ago) that all fans were 3pin,pwm wasn't really a thing yet. So connectors were square, flat sided with just a lip on one side, and the other was thicker. With pwm, they started keying the 3pin fan connectors, so they only fit the 3 necessary pins and only in 1 direction. That key also provides friction, something for the connector to grab onto and provide a stabilizing force, holding the connector in the port.

If that key is worn or cheaply made and not an exacting standard fit, it can leave the connector loose, as can use of cheap pin connectors on the wires inside the connector itself. They can be made of substandard tin with very little spring, and couple of uses they stretch and come loose.

Prebuilt companies like Dell and Lenovo are almost famous for using such cheap junk connectors and their answer is to hot-glue the connector to the port to prevent it falling out.