Troubleshooting

ALPON X5 AI · Troubleshooting · Power, LEDs, connectivity, NPU, OS, and ALPON Cloud
Troubleshooting

ALPON X5 AI troubleshooting

Diagnostic reference for the ALPON X5 AI edge AI computer. Each issue lists the observable symptom, the probable cause, and the minimal fix. Work through the categories in order: power, then LEDs and boot, then connectivity, then the DEEPX DX-M1 NPU, then the operating system and the ALPON Cloud agent.

How do I troubleshoot the ALPON X5 AI?

Start from the physical layer and move up. Verify power first (15 V / 27 W USB-C PD, DC 12 V to 32 V, or PoE+), confirm the Status LED reports a healthy state, check network links (LTE, Wi-Fi, Ethernet) in that order, verify the DEEPX DX-M1 NPU enumerates at /dev/dxrt0 with dxtop, and finally inspect ALPON X5 AI OS logs with journalctl -xe.

Before you troubleshoot

Most "dead on arrival" reports resolve with a 15 V / 27 W USB-C PD adapter or a 12 V to 32 V DC supply on the terminal block. Standard 5 V phone chargers do not negotiate enough voltage to boot the Raspberry Pi CM5 and DEEPX DX-M1 NPU. Start every diagnostic here.

Power and boot

The ALPON X5 AI accepts three independent power inputs: USB-C PD, DC terminal block, and PoE+. The device draws from the highest-voltage source. Under-voltage triggers restricted mode, which disables the NPU, USB ports, and ADDON header while keeping the Raspberry Pi CM5 and Ethernet alive.

Power

The device does not power on (no LEDs)

Symptom
Nothing lights up within 3 seconds of connecting power.
Cause
The adapter does not negotiate 15 V / 27 W. Standard USB-C phone chargers deliver 5 V only and the ALPON X5 AI will not boot.
Fix
  1. Use the 27 W USB-C PD adapter shipped with the device.
  2. If unavailable, power the DC terminal block from a 12 V to 32 V supply (45 W minimum at full load).
  3. Confirm wire polarity: Pin 1 = Chassis Ground, Pin 2 = DC Negative, Pin 3 = DC Positive.
  4. Try a different USB-C cable. Long or low-quality cables often drop PD negotiation.
Power

The device boots but the NPU, NVMe SSD, or USB ports are dead

Symptom
The Raspberry Pi CM5 comes up and Ethernet links, but /dev/dxrt0 is missing, the NVMe SSD does not appear, USB devices are not detected, and the ADDON port is inactive.
Cause
The device has entered restricted mode. Input voltage is below 12 V, so the PCIe bus and peripheral rails are disabled by design.
Fix
  1. Replace the 5 V source with a 15 V USB-C PD adapter or a 12 V to 32 V DC supply on the terminal block.
  2. For long DC cable runs, prefer a 24 V adapter with thicker conductors to compensate for voltage drop.
  3. Reboot after restoring nominal voltage so the PCIe bus re-enumerates.
Restricted mode is by design

Restricted mode prevents brownouts at low input voltage. The Raspberry Pi CM5 and both Ethernet ports stay alive; USB, PCIe (NVMe + DEEPX DX-M1), ADDON, and camera rails are disabled. AI inference is not available until the device leaves restricted mode.

Power

The device resets or throttles under heavy AI load

Symptom
The Raspberry Pi CM5 logs voltage or thermal warnings during sustained NPU inference and occasionally reboots.
Cause
The adapter delivers the minimum 27 W but cannot hold it under peak load, or the enclosure is mounted so airflow across the aluminum heatsink is blocked.
Fix
  1. Switch to a 45 W (15 V / 3.0 A) USB-C PD adapter or a DC supply sized for 45 W continuous.
  2. Mount the device with the cooling surface facing up and leave at least 25 mm clearance in enclosed cabinets.
  3. Verify with vcgencmd get_throttled that the Raspberry Pi CM5 is not hitting the under-voltage bit.
Hardware

The device boots in a reset loop

Symptom
The Raspberry Pi CM5 starts and powers down every few minutes without reaching a login prompt.
Cause
The hardware watchdog (SW1) is enabled but no userspace service is feeding it, so it resets the device every 5 minutes.
Fix
  1. Disconnect all power from the device.
  2. Move the SW1 switch to OFF to disable the hardware watchdog while you finish bring-up.
  3. Reapply power and verify the device stays up. Re-enable the watchdog once your application actively pets it.
Toggle switches with the device off

Always disconnect all power before flipping SW1 (Watchdog) or SW2 (Boot/Burn). Changing SW2 while powered can corrupt the Raspberry Pi CM5 eMMC.

LED states and what they mean

The ALPON X5 AI surfaces device health on the Status LED and the Cellular LED. Reading these two indicators is the fastest first diagnostic when you do not yet have shell access.

Green Blinking green Amber Red Off

What does each LED pattern indicate?

LED State Meaning and next action
Status Solid green Device is online and reachable in Sixfab Connect. No action needed.
Status Blinking green Boot or provisioning in progress. First boot can take up to 3 minutes while ALPON Cloud is reached and credentials are issued.
Status Solid red Cannot reach ALPON Cloud. Check LTE antenna torque, move the device for better RF, or connect ETHERNET 0 to an upstream router.
Status Off No power or the Raspberry Pi CM5 has not completed early boot. Start at Power and boot.
Cellular Solid green Cellular data session is up and passing traffic.
Cellular Amber Modem is registered but signal is weak. Reposition or upgrade to a higher-gain LTE antenna.
Cellular Red No cellular attach. Check eSIM activation, LTE band availability, and antenna connections.
Connectivity

The Status LED stays red after 3 minutes

Cause
The Sixfab Connect agent cannot reach the cloud. Cellular and Ethernet are both down, or the device has not completed provisioning.
Fix
  1. Plug a cable from ETHERNET 0 into an internet-connected router to give the device a known-good path.
  2. Hand-tighten the two LTE antennas on the SMA connectors labeled L.
  3. Wait two minutes. If still red, open the remote terminal or HDMI shell and run systemctl status sixfab-connect to inspect the agent.

Connectivity (LTE, Wi-Fi, Ethernet)

The ALPON X5 AI carries LTE Cat 4, dual-band Wi-Fi, and two Gigabit Ethernet ports. When more than one path is available, the Sixfab Connect agent handles failover in priority order. Most connectivity problems reduce to antenna, SIM, or link-order configuration.

Connectivity

The Cellular LED is red or amber

Cause
Weak LTE signal, missing or loose antenna, or the eSIM (eUICC) profile has not activated on the local network.
Fix
  1. Hand-tighten both antennas on the SMA connectors labeled L (LTE Main and LTE Diversity). Never connect the Wi-Fi antenna (RP-SMA male) to an LTE port.
  2. Move the device near a window or use an external high-gain antenna.
  3. Confirm the modem is attached and check signal quality:
    terminal shell
    mmcli -L
    mmcli -m 0 --signal-get
  4. If the modem reports registered but throughput is low, switch carriers from the ALPON Cloud console.
Connectivity

Wi-Fi does not connect or keeps dropping

Cause
The Wi-Fi antenna is missing, the SSID uses an unsupported security mode, or the device is on the edge of the access point's coverage.
Fix
  1. Install the supplied Wi-Fi antenna on the RP-SMA male port labeled W.
  2. Use WPA2-PSK or WPA3-Personal. Enterprise EAP profiles require extra setup via nmcli or Sixfab Connect.
  3. Connect from Sixfab Connect (Connect to Wi-Fi), or over SSH:
    terminal shell
    nmcli device wifi list
    nmcli device wifi connect "YOUR_SSID" password "YOUR_PASS"
Connectivity

ETHERNET 1 does not link up or shows low throughput

Cause
ETHERNET 1 is a USB-bridged Gigabit Ethernet port, not a native Raspberry Pi CM5 PHY. It shares the TUSB8020 hub upstream with one of the USB 3.0 ports. Heavy concurrent USB traffic reduces its throughput.
Fix
  1. Use ETHERNET 0 for performance-sensitive traffic. It is the native Raspberry Pi CM5 Gigabit Ethernet and the only PoE-capable port.
  2. If you must use ETHERNET 1, avoid attaching high-bandwidth USB 3.0 devices to the shared hub.
  3. Never connect a PoE source to ETHERNET 1. It does not accept PoE.
Power

PoE+ does not power the device

Cause
The injector is legacy IEEE 802.3af (not 802.3at Class 4), the cable is connected to ETHERNET 1 instead of ETHERNET 0, or your variant does not include the PoE module.
Fix
  1. Use an IEEE 802.3at (PoE+) Class 4 injector or switch that delivers 37 V to 57 V.
  2. Connect PoE to ETHERNET 0 only. ETHERNET 1 cannot accept power.
  3. Check the sticker on the enclosure; the PoE module is a factory option and cannot be field-added.

DEEPX DX-M1 NPU

The ALPON X5 AI is intelligented by DEEPX. The DEEPX DX-M1 delivers 25 TOPS at INT8 precision over PCIe. The kernel driver enumerates it as /dev/dxrt0 on ALPON X5 AI OS. Models reach the NPU through the ONNX → DXNN compiler path on a host PC, and execute on-device through dxrt-runtime (dx_engine for Python, dxrt_api.h for C++).

AI Runtime

/dev/dxrt0 is missing or dxtop reports no device

Cause
The device is in restricted mode (PCIe disabled), the kernel driver failed to load, or the DEEPX DX-M1 M.2 module is not seated correctly.
Fix
  1. Verify you are running at 12 V DC or 15 V USB-C PD minimum. See Power and boot.
  2. Check the driver and PCIe enumeration:
    terminal shell
    lspci | grep -i deepx
    lsmod | grep dxrt
    ls -l /dev/dxrt*
  3. If PCIe enumerates but the driver is missing, reinstall it:
    terminal shell
    sudo apt update
    sudo apt install --reinstall -y libdxrt
  4. If lspci does not list the DEEPX device, power down, open the enclosure, and reseat the DEEPX DX-M1 M.2 module. Apply ESD precautions.
AI Runtime

Python raises ImportError: No module named dx_engine

Cause
The script is running under the system Python. The dx_engine binding lives inside the bundled virtual environment at /usr/lib/libdxrt/dxrt-venv.
Fix
terminal shell
source /usr/lib/libdxrt/dxrt-venv/bin/activate
python -c "import dx_engine; print(dx_engine.__version__)"

For scripts, invoke the venv Python directly: /usr/lib/libdxrt/dxrt-venv/bin/python my_script.py.

AI Runtime

Cannot open /dev/dxrt0 inside a Docker container

Cause
The container was started without the NPU character device mapped in, or without the privileges needed to attach to it.
Fix

Start the container with the device and --privileged:

terminal shell
docker run --rm --privileged   --device /dev/dxrt0   -v /opt/models:/models   alpon-infer:latest

For docker-compose, set privileged: true and devices: ["/dev/dxrt0"].

AI Runtime

Model fails to load with an out-of-memory error

Cause
The compiled .dxnn footprint exceeds the DEEPX DX-M1's 4 GB on-chip memory. The NPU has its own dedicated memory pool, independent of Raspberry Pi CM5 system RAM.
Fix
  1. Recompile with a lower input resolution (for example 640×640 instead of 1280×1280).
  2. Switch to a lighter model variant (nano or small instead of large or x).
  3. Quantize or prune the model before re-exporting to ONNX, then recompile with dxcom.
AI Runtime

YOLO inference runs at a very low FPS on the ALPON X5 AI

Cause
The model was compiled without PPU (post-processing unit) support. Post-processing (NMS, box decoding) then runs on the Raspberry Pi CM5 CPU and becomes the bottleneck.
Fix
  1. Recompile the ONNX graph with a config that enables the PPU. Run dxcom on a host PC:
    terminal (host PC) shell
    dxcom   -m /path/to/yolov8n.onnx   -c yolov8n_config.json   -o yolov8n-output
  2. Use a config with a ppu block, calibration settings, and the matching preprocessing pipeline:
    yolov8n_config.json json
    {
      "inputs": {
        "images": [1, 3, 640, 640]
      },
      "calibration_num": 100,
      "calibration_method": "ema",
      "train_batchsize": 32,
      "num_samples": 1024,
      "default_loader": {
        "dataset_path": "./calibration_dataset",
        "file_extensions": ["jpeg", "jpg", "png", "JPEG"],
        "preprocessings": [
          { "resize": { "mode": "pad", "size": 640,
                        "pad_location": "edge",
                        "pad_value": [114, 114, 114] } },
          { "div": { "x": 255 } },
          { "convertColor": { "form": "BGR2RGB" } },
          { "transpose": { "axis": [2, 0, 1] } },
          { "expandDim": { "axis": 0 } }
        ]
      },
      "ppu": {
        "type": 1,
        "conf_thres": 0.25,
        "num_classes": 80,
        "layer": [
          { "bbox": "Mul_441", "cls_conf": "Sigmoid_442" }
        ]
      }
    }
  3. Redeploy the resulting .dxnn. PPU-compiled nano-class YOLO models reach roughly 50 FPS at 1280×720 and 20 to 25 FPS at 1920×1080.
  4. Monitor with dxtop to confirm the NPU is saturated rather than the CPU.
Output node names depend on your ONNX export

The bbox and cls_conf layer names (Mul_441, Sigmoid_442) come from the YOLOv8 ONNX graph and will differ across exports. Open the model in Netron to confirm the correct node names before compiling.

AI Runtime

dxcom reports an unsupported operator

Cause
The ONNX graph contains an attention block, transformer layer, or another operator outside the DEEPX DX-M1 supported set. The current dxrt-runtime targets image-based CNNs; transformers are not yet supported.
Fix
  1. Switch to a CNN-based equivalent (YOLOv5/v7/v8, SSD, ResNet, MobileNet, EfficientNet, U-Net).
  2. If you must keep a transformer head, run it on the Raspberry Pi CM5 CPU and offload only the CNN backbone to the NPU.
  3. Check the DEEPX release notes for the current supported-operator list before compiling.

ALPON X5 AI OS and SSH

ALPON X5 AI OS is a Sixfab-maintained ARM64 Debian-based Linux distribution for the Raspberry Pi CM5. The default user is alpon with password sixfab. The hostname is derived from the MAC address, so the device is reachable over mDNS as alpon-<MAC>.local.

Software

I cannot SSH into the device

Cause
Wrong username, wrong IP or hostname, firewall blocking port 22, or the device is on a different subnet than your workstation.
Fix
  1. Connect with the correct user: ssh alpon@<DEVICE_IP> or ssh alpon@alpon-<MAC>.local.
  2. If the local network is unreachable, use the browser-based remote terminal in Sixfab Connect. It works even when only cellular is up.
  3. As a last resort, attach HDMI and a USB keyboard for local login.
Software

I forgot the password or locked myself out

Fix
  1. Open the Sixfab Connect remote terminal. It authenticates through the cloud agent and does not require your local password.
  2. From that shell, run sudo passwd alpon to set a new password.
  3. If the remote terminal is unreachable and you have no HDMI access, contact Sixfab support with the device serial number for a recovery procedure. Do not attempt to re-flash the eMMC without guidance.
Do not delete the alpon user

The alpon account is used internally by Sixfab Connect and other system services. Change the password and, if you need a separate admin identity, create a new user with sudo rights. Deleting alpon breaks core system functions.

Software

apt update or apt upgrade fails

Cause
No internet path, broken GPG key for the Sixfab or DEEPX repositories, or a partial upgrade that left dpkg in an inconsistent state.
Fix
terminal shell
# Verify connectivity first
ping -c 3 deb.debian.org

# Repair any half-configured packages
sudo dpkg --configure -a
sudo apt -f install

# Refresh and retry
sudo apt update
sudo apt upgrade -y

If a repository's GPG key is missing, reinstall it from the Sixfab or DEEPX documentation before running apt update again. Reboot when a kernel or firmware package was upgraded.

Hardware

Nothing appears on HDMI

Cause
The HDMI display was connected after boot, the cable does not support the negotiated mode, or the Raspberry Pi CM5 has not completed early boot.
Fix
  1. Plug HDMI before powering on. Hot-plug detection is best-effort on the Raspberry Pi CM5.
  2. Use a certified HDMI cable and a monitor that supports 1080p at 60 Hz.
  3. If the monitor stays blank, verify over SSH that the device booted, then reboot with HDMI already connected.

ALPON Cloud and provisioning

Every ALPON X5 AI ships with the Sixfab Connect agent. The agent registers the device on first boot and keeps it reachable through ALPON Cloud. Provisioning requires any one upstream path (LTE, Wi-Fi, or Ethernet) and a reachable connect.sixfab.com.

Software

The device appears Offline in Sixfab Connect

Cause
No upstream path is currently reachable, or the agent lost its session and has not re-attached.
Fix
  1. Check the LED legend above. If the Cellular LED is red, fall back to Ethernet by plugging ETHERNET 0 into a wired router.
  2. From a local shell, inspect the agent:
    terminal shell
    systemctl status sixfab-connect
    journalctl -u sixfab-connect -n 200
  3. If the agent is stuck, restart it:
    terminal shell
    sudo systemctl restart sixfab-connect
Software

The QR code on the label does not scan

Fix
  1. In Sixfab Connect, choose Manual registration.
  2. Enter the serial number printed next to the QR code.
  3. Follow the on-screen prompts to bind the device to your organization.
Software

Deployments queued in ALPON Cloud do not reach the device

Cause
The device is offline, the container image exceeds available NVMe free space, or the image was not built for ARM64.
Fix
  1. Confirm the device is Online and the Sixfab Connect agent is healthy.
  2. Rebuild your image for ARM64: docker buildx build --platform linux/arm64 -t my-image .
  3. Check available disk with df -h /. Prune unused images: docker image prune -a.

Before you contact support

Running through these checks covers more than 90% of field issues and gives Sixfab support the context needed for a fast resolution. Run them top to bottom; each step takes under a minute.

Pre-support checklist

Run these seven checks before opening a ticket

01

Power source

15 V / 27 W USB-C PD or 12 V to 32 V DC. No under-voltage flag.

$ vcgencmd get_throttled
02

Switch positions

SW1 (Watchdog) and SW2 (Boot/Burn) both OFF. Toggle only with all power disconnected.

SW1 · SW2 · OFF
03

LED state

Note the exact state of Status and Cellular. See the LED reference.

Status · Cellular
04

Antennas seated

Four SMA connectors hand-tight. Wi-Fi/Bluetooth = RP-SMA male; LTE Main, LTE Diversity, GNSS/GPS = SMA female.

L · L · W · G
05

Network path

At least one of LTE, Wi-Fi, or ETHERNET 0 reaches the internet.

$ ping -c 3 8.8.8.8
06

NPU enumeration

dxtop shows /dev/dxrt0 with live utilization and temperature.

$ dxtop
07

Device serial number

Read it from the enclosure label, next to the QR code. Include it in the ticket.

SN-XXXXXXXX

Collecting a support bundle (optional)

If you can run a shell on the device (SSH or HDMI), this single block captures the journal, kernel ring buffer, PCIe topology, and OS release into one archive. Attach it to your ticket if you can; otherwise the items in the checklist above are enough to start.

terminal (on the ALPON X5 AI) shell
# Single-shot bundle, run on the device over SSH
sudo journalctl -b -n 2000 > ~/alpon-journal.log
dmesg > ~/alpon-dmesg.log
lspci -vv > ~/alpon-lspci.log
cat /etc/os-release > ~/alpon-os.log
tar czf ~/alpon-support.tar.gz ~/alpon-*.log
# Copy the archive to your computer with scp, WinSCP, or Cyberduck.
No shell access?

Send a plain-text email with the device serial number, the observed LED state, and a one-line description of what you were doing when the issue appeared. Sixfab support can guide you through log collection from there.

Still stuck? Get help from Sixfab

Reach out with your support bundle and the LED state you observed. Typical first response in one business day.