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No Video Signal / No Unit Present — Troubleshooting Guide

Dotan Asselmann
Updated

What is this alert?

This guide covers two related issues that may be reported manually via PagerDuty:

  • No Video Signal: The cable is connected but the unit is not receiving a video signal from the source.
  • No Unit Present: A room that should have a theator unit does not have one physically present.

These issues are typically reported manually by staff or identified during monitoring checks, rather than triggered by automated alerts.

Impact

  • Cases in the affected room are not being recorded.
  • For "No Video Signal": the unit is connected and online, but cannot see any video — the issue is with the video source or cable signal.
  • For "No Unit Present": there is no theator device in the room at all.

Step 1: Acknowledge the Alert

Open the alert in the Incidents Dashboard and click Acknowledge.

Incidents Dashboard showing active alerts

Step 2: Check the Monitoring Pages

  1. Go to Monitoring > Units in the theator app.

  2. For No Video Signal:

    • The unit will show as connected (green)
    • The video input will show as connected but with no active signal
    • No frame preview will be displayed

  3. For No Unit Present:

    • The room may show with no unit assigned
    • Or the assigned unit may show as offline

Step 3: Go to the Room

For No Video Signal:

  1. Check the video source equipment:

    • Is the surgical tower / camera system powered on?
    • Is it outputting video? Check the tower's own display if available.
    • Is the correct output port being used?

  2. Check the cable connections:

    • Re-seat the cable at both ends (unit and tower)
    • Try a different output port on the surgical tower if available
    • Try a different cable if you have a spare

  3. Check cable type compatibility: Make sure the cable type (SDI/HDMI) matches both the unit input and tower output ports.

For No Unit Present:

  1. Check if the unit was moved: Ask OR staff if the unit was relocated to another room.
  2. Check storage areas: The unit may have been moved to storage during cleaning or room reconfiguration.
  3. For roaming/mobile units: Check if the cart was wheeled to a different location.
  4. If the unit is found, bring it back to the room, power it on, and connect it.

Step 4: Verify the Fix

  1. Go to Monitoring > Units — confirm:

    • The unit shows as connected
    • Video inputs show as active with frame previews

  2. If a case is scheduled soon, verify the room shows as ready on Monitoring > Rooms.

Step 5: Resolve the Alert

  1. Return to the Incidents Dashboard.

  2. Click Resolve on the incident.

  3. Add a note, for example:

    • "Surgical tower was powered off. Turned on and video signal restored."
    • "Wrong output port on tower. Switched to HDMI output 2."
    • "Unit was moved to OR 3 for cleaning. Brought back and reconnected."
    • "Replaced SDI cable — old cable had no signal."

When to Escalate

Escalate to theator support if:

  • The surgical tower is on and outputting video, but the unit still shows no signal
  • You've tried multiple cables and ports with no success
  • The unit is missing and cannot be located
  • You suspect a hardware issue with the unit's video input

When escalating, include: unit name, room name, video source equipment model (if known), cables/ports tried, and what you observed.

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