Two OS0-128 LiDARs failed under same setup: no Ethernet link (no LED), earlier 100 Mbps fallback, and motor shutdown — detailed debugging included

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1

Hi,

I am reporting failures in two OS0-128 LiDAR sensors. Both sensors were working correctly earlier, but have now failed under the same setup. I am providing detailed observations and debugging steps below.

System Setup

  • Sensors: 2 × OS0-128

  • Host systems:

    • Jetson AGX Orin

    • Laptop (used for cross-checking)

  • Network:

    • Direct Ethernet connection (no switch)

  • Power:

    • External DC adapter

Power Measurement

  • Measured using multimeter:

    • Output voltage ≈ 24.16V (DC)

  • Measurement taken without load (adapter powered, LiDAR not connected)

Failure Timeline

First LiDAR (failed ~10 days ago)

  1. Initially working normally

  2. Then started showing:

    • Intermittent detection via link-local IP (~10% success rate)

    • Link speed reduced to 100 Mbps (instead of expected 1000 Mbps)

  3. After some time:

    • Completely stopped detecting

    • No response over network

    • No LED activity on Ethernet port (both LiDAR and host side)

Second LiDAR (failed today)

  1. Initially working normally

  2. Then:

    • Motor rotates correctly at startup

    • After ~5 minutes, motor automatically stops (no manual command)

  3. Current condition:

    • In some cases, no Ethernet LED activity (no link)

    • Behavior becoming similar to first LiDAR

Network-Level Observations

  • Tested with multiple Ethernet cables:

    • Same cables work perfectly with other LiDAR sensors

  • Tested with multiple host systems:

    • Jetson AGX Orin

    • Laptop

  • In failing condition:

    • No Ethernet LED on either side → indicates no physical link (Layer 1 failure)

  • Earlier stage showed fallback to 100 Mbps before complete failure

Key Technical Observations

  • Issue is not related to:

    • IP configuration

    • ROS / SDK

    • Host system

  • Problem exists at physical/network layer (Ethernet link not established)

  • Failure progression observed:

    1. Stable operation

    2. Degraded link (100 Mbps fallback)

    3. Intermittent detection

    4. Complete link failure (no LED)

Suspected Cause

Based on observations, I suspect a possible power-related issue:

  • Although measured voltage is ~24.16V (no load),

  • There may be:

    • Voltage instability under load

    • Transient spikes

    • Insufficient current supply

  • This could potentially affect:

    • Ethernet PHY (causing no link / no LED)

    • Motor controller (causing shutdown after few minutes)

Questions

  1. Can power instability (even if nominal voltage is correct) damage:

    • Ethernet PHY (leading to complete link failure)?

    • Motor control system (leading to shutdown)?

  2. Is the observed transition from 100 Mbps → no link a known failure pattern?

  3. Does this behavior indicate permanent hardware damage?

  4. Are there any recovery or diagnostic steps recommended before considering RMA?

Additional Data (available if required)

  • Voltage measurement under load (can provide)

  • Adapter specifications

  • Sensor logs

  • ethtool output

Any guidance on root cause analysis or next steps would be highly appreciated.

Thank you.

2

@Brahmaiah

Could you confirm if you are using an Ouster Interface Box (I-Box) to connect and power the LiDARs, or if you are using a custom cable/power setup?

Given the symptoms you described (especially the Ethernet link degradation from 100 Mbps to complete failure, and the motor stopping), we highly recommend opening a ticket directly with the Ouster Support team so we can formally investigate this.

If you are still able to connect to the sensors (even intermittently), please try to pull the diagnostics file from the web UI and attach it to your support ticket. You can find instructions on how to retrieve that file here: