John Chad, Bachelor Degree in Computer Science & Computer Engineering.
Russel Collins
This is a common question for people who are setting up their new computer or perhaps troubleshooting their CPU or motherboard, however, the answer isn’t so simple as it depends on what fans we’re talking about and what the most common result should be when powering up with no processor.
Will fans spin without CPU?
They will! All fans will spin when you turn on your computer even if you have no CPU. However, your computer will immediately shut down due to the lack of CPU which will make them stop spinning right away, the computer won’t boot without a processor.
Other Common Questions
Below we’ll answer a few different commonly asked questions related to troubleshooting, if you have any more you would like us to add simply write a comment below and we will update it!
Does the CPU power the fans?
No, not directly. The computer will boot and beep indicating that it’s missing a component (Processor) which will make your cooler stop spinning immediately after powering on so if you hear them spin up when starting your PC then this indicates they are being powered by another source such as a PSU or motherboard fan header. If the other components in the system aren’t getting enough power from these sources though then things will start to fail pretty quickly!
Is it normal for CPU fans not to spin?
If the computer is turned on and they are properly connected then it can be an issue with the motherboard being faulty and not being able to deliver the power from the PSU into the components connected to the motherboard. If absolutely everything is powered and the computer is running but the fans aren’t spinning then the cooler might be either not properly connected or faulty.
Can a power supply and motherboard turn on without a CPU?
Yes! Again, you can turn on your computer even without having a processor in your computer, however, it will immediately shut down.
The computer won’t post but fans spin
This can be due to a number of reasons such as not having enough power or the CPU being faulty. If you’re testing your computer and it’s not posting, try disconnecting all unnecessary peripherals and see if that fixes the issue. The cooler will continue spinning when there is no post because they are powered by other sources in the system.
Can you use a Processor with no Cooler?
Well, technically, you can! However, your processor will overheat extremely fast and you might even damage it due to overheating, a cooler is absolutely necessary no matter what, so make sure you have a cooler & it’s properly plugged in when you turn on your computer.