ZimaBoard 2 Fan Installation Guide & PWM Control

One-sentence overview: From the shipping list, to wiring & installation, then set PWM in BIOS—all in one go.
Add active cooling to your ZimaBoard 2 mini NAS / home server / self-hosted node for sustained NVMe, 10GbE, and local AI workloads.

Shipping List

  • 1x PWM fan module (with 4-pin PWM cable)
  • 1x T5 Torx screwdriver (rear cover)
  • 1x T10 Torx screwdriver (fan mounting)

ZimaBoard 2 fan installation kit—PWM fan module with 4-pin cable and T5/T10 Torx screwdrivers (shipping list)

Fan Installation

  • Shut down the device and unplug the 12V power adapter.
  • Wait until the Power LED is off and the heatsink is cool.
  • Work on a clean, ESD-safe surface.

Steps

  • Remove rear cover (T5): Unscrew the T5 screws and lift the cover straight up.

ZimaBoard 2 rear cover removal with T5 Torx screwdriver—loosen four screws to open the back panel (fan installation step).

  • Plug 4-pin PWM fan cable: Locate the CPU_FAN header; align the keyed connector and insert.

    ZimaBoard 2 CPU_FAN 4-pin header wiring—align the keyed 4-pin PWM connector and plug in (fan installation step), CLR_CMOS nearby.

  • Route cable & refit cover: Lead the cable through the side notch; reinstall the rear cover and tighten the T5 screws evenly.

    ZimaBoard 2 side notch cable routing—PWM fan cable exiting through the chassis notch to prevent pinching; refit rear cover and tighten screws (fan installation).

  • Mount the fan (T10): With the airflow into the fins (per diagram), fasten the fan to the heatsink using the T10 screws; secure firmly without over-torque.

    ZimaBoard 2 fan mounting with T10 Torx—secure the fan bracket to the heatsink, airflow toward the fins; cable routed through the side notch (installation step).

  • Congratulations! — Installation complete.

    ZimaBoard 2 fan installation complete—fan bracket secured to the aluminum heatsink, airflow toward the fins, cable routed through the side notch (final result).

Set PWM in BIOS (if needed)

  • Power on and press Delete to enter BIOS Setup.

  • Open Hardware Monitor.

    ZimaBoard 2 BIOS—Advanced > Hardware Monitor screen for fan control and PWM settings (AMI Aptio).

  • Choose your preferred fan control mode (e.g., PWM with a curve, or a fixed duty).

    ZimaBoard 2 BIOS—CPU Fan Control mode with PWM settings: Start Temperature, Full-Speed Temperature, Fan Start PWM, and PWM Slope (AMI Aptio).

  • Save & Exit (F10), then confirm the fan spins after reboot.

    ZimaBoard 2 BIOS—Save & Exit (F10) screen; choose “Save Changes and Exit” to apply fan/PWM settings (AMI Aptio).

BIOS Fan Control Options (Explanation)

  1. PWM Auto Mode
  • Fan Start Temperature: Fan control engages automatically once CPU temp ≥ start point (range: 0–100 °C).
  • Fan Full-Speed Temperature: When CPU temp ≥ this point, the fan jumps to 100% (range: 0–100 °C; must be greater than Start Temperature).
  • Fan Start PWM: Initial (minimum) fan speed after ZimaBoard 2 powers on (range: 0–255; 255 = 100%).
    Example: To set “Fan off when temperature is below Fan Start Temperature”, set to 0.
  • PWM SLOPE SEETING: Duty increment for each +1 °C rise (range: 0-15).

    ZimaBoard 2 BIOS—CPU Fan Control in PWM Auto Mode: start temperature limit, full-speed temperature limit, fan start PWM, and PWM slope setting (AMI Aptio).

  1. Fixed Duty Mode
  • Fixed Fan Duty: Run the fan at a constant speed (range: 0–255; 255 = 100%).
    **Note**: The PWM value (0–255) represents the duty cycle / effective drive level rather than a direct RPM percentage. Fan speed is not linear with PWM

    ZimaBoard 2 BIOS—CPU Fan Control in Fixed Duty (Manual) Mode: set Manual PWM value (0–255, 255=100%) (AMI Aptio).

Troubleshooting

  • Fan won’t spin:
    • Reseat the 4-pin connector; ensure the header/mode is enabled.
    • Verify the fan’s minimum PWM start threshold (don’t set duty too low, each fan has a different minimum starting PWM).
  • Noise / vibration: Re-align the fan and tighten the screws.
  • Won’t power on after install: Remove the fan PWM lead and try again. If the CMOS reset button was pressed accidentally, the first boot may take ~2 minutes for POST/self-test.
  • Fan doesn’t stop at PWM 0：This is by design to prevent stalling and ensure minimum cooling. Many fans have a hardware-enforced minimum PWM speed.