Troubleshooting

Common issues and solutions for the Interceptor Carrier Board

  5 minute read  

This guide covers common issues encountered with the Interceptor Carrier Board and their solutions.

Power Issues

System won’t power on

Symptoms: Power LED doesn’t illuminate, no activity.

Solutions:

  1. Verify ATX PSU is switched on (check rear switch)
  2. Check that 24-pin ATX connector is fully seated
  3. Verify PSU is functional (test with another system or PSU tester)
  4. Check front panel power button wiring on J2

System powers off randomly / crashes

Symptoms: System runs for a while then shuts down or freezes.

Likely Cause: Unstable +3.3V rail from PSU.

Solutions:

  1. Replace PSU - This is the most common cause. Low-quality PSUs cannot maintain 3.3V under low load conditions typical of Pi-based systems
  2. Use a Flex ATX PSU from the Exaviz Store or a quality brand (Corsair, EVGA, Seasonic)
  3. Check voltage with multimeter (should be 3.3V ±5%)

System unstable under load

Symptoms: Crashes when accessing SATA drives or using PoE.

Solutions:

  1. Verify PSU wattage is adequate for your configuration
  2. Check 12V rail capacity (especially with PoE boards)
  3. Ensure all power connections are secure

Boot Issues

Keyboard not working at boot menu

Symptoms: Keyboard works after OS loads but not in boot menu or during early boot.

Cause: Some keyboards (especially Apple keyboards) are not recognized during early boot stages.

Solution: Use a standard PC/Windows keyboard for boot menu navigation and initial setup. Your preferred keyboard can be used after the OS loads.

“GPT no bootable partition” error

This error has two common causes:

Cause 1: CM5 USB boot limitation

CM5 cannot boot from USB 2.0, and the Interceptor board only has USB 2.0 ports.

Solutions for CM5:

  1. Use SD card boot - If CM5 has blank eMMC, it will boot from SD
  2. Flash eMMC - Use a separate Raspberry Pi IO Board (CM4 or CM5 IO Board both work) with rpiboot to flash the OS to eMMC, then install CM5 on the Interceptor

Cause 2: Windows flashing issue

Flashing OS images from Windows can sometimes create invalid GPT partition tables that prevent booting. This affects CM4 and CM5 when booting from USB flash drives.

Solutions for Windows flashing issues:

  1. Flash from Linux or macOS - This consistently resolves the issue
  2. Flash to SD card or eMMC instead of USB flash drive
  3. Try a different tool - Raspberry Pi Imager or Balena Etcher

See FAQ for more details.

No video output

Symptoms: HDMI displays show no signal.

Solutions:

  1. Try the other HDMI port (J4 or J5)
  2. Banana Pi CM4: Only HDMI0 (J4) works - this is a known limitation
  3. Check config.txt for HDMI configuration issues
  4. Try a different HDMI cable or monitor
  5. Connect via SSH to verify system is booting

SD card not detected

Solutions:

  1. Try a different SD card
  2. Reformat card as FAT32 (for boot partition)
  3. Re-flash the OS image
  4. Check SD card slot for debris or damage

Network Issues

Ethernet switch not detected (RTL8367RB err=-19)

Symptoms:

  • dmesg shows rtl8367rb: err=-19 or similar
  • No DHCP IP address on WAN port
  • Network interfaces missing

Likely Cause: Usually indicates a bad CM4 module or improper seating.

Solutions:

  1. Reseat the CM4 module
  2. Check CM4 connector pins for damage
  3. Test the CM4 on a Raspberry Pi IO Board if available
  4. Try a different CM4 module

No network connectivity

Symptoms: Cannot ping or SSH to the device.

Solutions:

  1. Check Ethernet cable connections
  2. Verify link LEDs on the RJ-45 ports are illuminated
  3. Try a different port on J8
  4. Check IP configuration:
    ip addr show

Only some ports working

Solutions:

  1. Check individual port LEDs
  2. Try different cables
  3. Check switch driver is loaded:
    sudo dmesg | grep rtl

Storage Issues

SATA drives not detected

Symptoms: Drives not showing in lsblk.

Solutions:

  1. Check SATA and power cables are connected
  2. Verify drives work in another system
  3. Check controller status:
    sudo dmesg | grep -i "sata\|jmb\|ahci"
lspci | grep -i sata

Poor SATA performance

Symptoms: Slow transfer speeds.

Solutions:

  1. Check for SATA errors:
    sudo dmesg | grep -i error
  2. Verify AHCI mode is enabled
  3. Check cable quality (use quality SATA III cables)

Fan Issues

Fans running at full speed

Expected Behavior: The fan headers (M1-M4) do not support PWM speed control. Fans will always run at full speed when connected.

Workaround: Use low-noise fans or external fan controllers if noise is a concern.

Fans not spinning

Solutions:

  1. Verify fans are 12V DC (not PWM-only)
  2. Check fan connections
  3. Test fans on another 12V source

Serial Console Issues

Cannot connect via UART

Solutions:

  1. Use a 3.3V USB-to-Serial adapter (not 5V!)
  2. Check TX/RX are not swapped:
    • Adapter TX → Board RX (J2 Pin 6)
    • Adapter RX → Board TX (J2 Pin 5)
    • Connect GND
  3. Use correct serial settings: 115200 8N1

Video Issues

No HDMI output (suspect bad CM4)

Symptoms: No video on either HDMI port, but system is accessible via SSH/network.

Diagnostic Rule: When HDMI issues occur but the system otherwise boots (network works, SSH works), the most likely cause is a defective CM4 module or improper seating.

Steps:

  1. Reseat the CM4 - Remove and reinstall, ensuring proper alignment
  2. Check CM4 connector pins - Pins can become damaged invisibly
  3. Test on a Raspberry Pi IO Board - If available, test the CM4 on a standard Pi IO Board. If the green LED doesn’t light, the CM4 is defective
  4. Try a known-good CM4 - If you have another CM4, swap to verify

No display on HDMI1 (Banana Pi)

Expected: This is a known limitation. Only HDMI0 (J4) works with Banana Pi CM4.

4K resolution issues

Solutions:

  1. Verify monitor and cable support HDMI 2.0
  2. Check config.txt settings:
    hdmi_enable_4kp60=1

Getting More Help

If you’ve tried these solutions and still have issues:

  1. Gather Information:

    # System info
uname -a
cat /etc/os-release

# Hardware detection
lsusb
lspci
lsblk

# Recent errors
sudo dmesg | tail -100

  2. Contact Support:

Next Steps

Last modified January 11, 2026