CPU Fan Not Working

[mevcutonur]

                  I have an HP Compaq dc5800 Microtower computer. A few months ago I upgraded my CPU to Intel Core Quad Q9550 which heats up more than the older CPU so I wanted to also buy a fan for it. (There used to be only a heatsink and it was enough for that CPU) After buying the CPU Fan I was unable to connect it to the motherboard because there is only one socket for a fan and the BIOS gives an error if you unplug the chassis fan. Even if you could get around that error the new bought fan still didn't work because they re-wired the header just so you don't plug in anything else. Learning about this, I wanted to connect the fan to the PSU directly. I have 4 free cables coming out of my PSU. 3 of them are SATA cables, P4, P5 and P8. The other one is a 4-pin floppy cable, P7. So I bought a SATA to 4-pin fan cable from the internet. After trying all three SATA cables I couldn't get the fan to work. I tried connecting the fan cable as 3-pins on the left side, the right side and as a 4-pin normally.

 

I measured the voltage on the fan cable and got 5V (starting voltage is 7V) on one of the pins and 12V (recommended voltage) on another.

• https://imgur.com/gallery/pnS33CR

I assume this means the cables work fine and they're getting enough power. So what could be the problem here? The fan can turn freely manually. The LEDs don't light up and the fan doesn't spin like it's not getting power. Is what I did enough to know it's getting power or is there anything else I can do to make sure of that? Or could the fan be completely broken, and if so how can I test that? Any help is highly appreciated, thanks.

[Mdaisley2]

Ya, I had a similar problem with some 5v argb fans I wanted to hook up to my motherboard. But my mohterboard only had a 12v rgb header so I had to buy a 12v to 5v argb controller. In your case I think it would be best to either buy a different motherboard that has the right connections or buy a different fan. What cpu and fan did you buy? I think it might just be the fan or the sata to 4pin fan cable just doesnt work with this fan.

[mevcutonur]

It's an old PC and all of it's components are old. I don't really have the choice of replacing the motherboard. Also, the fan is a very cheap basic thing, but I don't need a good fan for this PC so it's fine. I might buy a new one but first I want to make sure the problem is with the fan. I'm looking for a way to check that.