Anyone know the correct size of the case fan in the Studio XPS 8100 desktop? It's either 92mm or 90mm. The part number on the label is:
It's a 92mm square by 25 mm fan - but. The but is that it's a proprietary 3-wire fan with a thermistor on it - if you replace it with a non-Dell fan, you will get a "fan failed" error each time you boot the system.
If you don't want to see the error (which can't be disabled) you need to replace it with an OEM Dell fan.
Roger the three wires, but are you sure it's a proprietary design? There are plenty of third-party 3-wire case fans. The third wire is the thermistor. On 4-wire case fans, the fourth wire allows the fan speed to be controlled (if the BIOS supports it.)