PC Fans Not Spinning or Showing 0 RPM? How to Fix It

Short answer: First check the fan is seated on a working header and its fan curve isn't set to 0%. A fan that spins but reads 0 RPM has lost its speed signal, usually through a splitter. A fan that won't spin at all on an NZXT controller may have tripped that channel's power limit, so spread the fans across more channels.

A dead fan is rarely a dead fan. Most of the time it's a connection, a setting or a power limit. You can find out which in a few minutes without buying anything.

Is it not spinning or just reading 0 RPM?

These look like the same problem in CAM or BIOS, but they aren't. Open the side panel and look at the fan while the PC is on.

Step 1: Check the connection

Shut down and switch off the power supply before you touch anything inside. Then:

1. Push the fan's power plug firmly onto its header. This is the 3-pin or 4-pin fan cable, not the RGB cable.
2. If the fan runs through an NZXT controller, reseat the controller's own power cable as well.
3. Move the fan to a different header or controller port and test again.
4. Plug a fan you know works onto the suspect header.

That last swap tells you where the fault is. If the good fan works on the suspect header, the original fan is the problem. If the good fan stops too, the header or port is.

Fans on an NZXT controller only get CAM control while CAM can see the controller. If the controller is missing from CAM, start with our guide to NZXT CAM not detecting your device.

Step 2: Check the fan curve

Some people set their curves to zero or near zero at low temperatures to keep a PC silent. If the curve is set that way, the fan stopping at idle is just the curve doing its job.

In CAM, open the Cooling tab and click the fan's channel to see its curve. If the curve sits at 0% for your current temperature, drag the nodes up or pick the Silent or Performance preset to start from something sensible. Our guide to setting fan curves in NZXT CAM walks through every option.

Fans on an NZXT N-Series motherboard are set in CAM too. On any other motherboard, the headers follow the curve in your BIOS instead. The fan settings usually sit under a section called hardware monitor or fan control. Check the header isn't set to stop at low temperatures.

Step 3: Check you're under the power limit

Every fan header and controller port has a power limit. Go over it on a motherboard header and the fans can run slower than they should or, worse, damage the header or melt a splitter's cables. On an NZXT controller, over-current protection cuts power to the channel completely, which looks exactly like a dead fan.

Work out your fans' draw with one sum: 12V multiplied by the total current in amps. The current is on the fan's sticker, box or product page, written like DC 12V 0.55A. Add up every fan on the same header, including any on a splitter.

Three F120X fans on a 12W header is well over the limit. Your motherboard manual lists the real limit for each header. On most NZXT fans the RGB runs on its own cable, so it doesn't count toward the fan header's draw.

A splitter doesn't add power. It shares the limit of the header it's plugged into. If you're over, spread the fans across more headers or use a powered fan controller like the NZXT Control Hub, which takes its own power from the PSU. Our guides to how many fans one header can run and fan controllers vs splitters go deeper.

Step 4: Spinning but showing 0 RPM? Check the speed signal

The RPM reading comes from one pin on the fan's cable, called the tach (or tachometer) pin. If that signal doesn't reach the header, you get 0 RPM from a fan that's spinning happily.

Splitters are the usual cause. Most only pass the speed signal through one of their connectors and leave the pin out on the rest. Make sure at least one fan is plugged into the full connector. If you only have one or two fans on the splitter, put one of them on it.

• Don't mix PWM (4-pin) and DC (3-pin) fans on the same splitter. It causes detection problems.
• Use the same fan model on a splitter for the most even speeds.
• In CAM, a detected fan shows PWM or DC in the top-right corner of its fan curve. No label means the controller can't see a fan on that channel.

If a fan you know works also reads 0 RPM on that port, the port is faulty. Contact support about the controller or motherboard.

Frequently asked questions

My fan's RGB lights up but the fan doesn't spin. Why?

Most RGB fans have two cables: one for the lighting and one for the motor. Lights mean the RGB cable is fine and tell you nothing about the fan cable, so check the 3-pin or 4-pin fan cable is plugged in. Single-frame fans like the F360 RGB Core run lighting and motor on one 8-pin cable. If one of those lights up without spinning, check its fan curve and power limit in Steps 2 and 3.

Can I plug a case fan into CPU_FAN or AIO_PUMP?

Yes, if you've run out of system fan headers. They're electrically the same as SYS_FAN headers. Two catches: CPU_FAN warns you when it reads 0 RPM, which is useful for your CPU cooler. And AIO_PUMP often runs at 100% by default, so a case fan on it will be loud until you lower its speed in BIOS.

My graphics card fans aren't spinning. Is it broken?

Probably not. Many graphics cards stop their fans at low temperatures to stay quiet, then spin them up when you start a game. If they spin under load, they're working as designed. If they never spin and the card overheats, contact the card's maker.

Does 0 RPM mean my fan is dead?

Not on its own. Look at the fan. If it's spinning, the fan is fine and only the speed reading is missing. If it's not spinning on any header, including one where another fan works, the fan has likely failed.

Will a fan controller fix fans that won't spin?

If the cause is a power limit, yes. A fan controller has its own power from the PSU, so it can run fans that are too much for one motherboard header. It won't fix a loose cable or a fan curve set to zero, so check those first.

Still not spinning?

If a fan won't spin on any header or port while a known-good fan works in the same spot, the fan has failed. If the problem follows the header or port instead, it's the controller or motherboard. Either way, contact NZXT Support with your proof of purchase for NZXT hardware.