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.
Step 2: Check the Monitoring Pages
Go to Monitoring > Units in the theator app.
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
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:
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?
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
Check cable type compatibility: Make sure the cable type (SDI/HDMI) matches both the unit input and tower output ports.
For No Unit Present:
Check if the unit was moved: Ask OR staff if the unit was relocated to another room.
Check storage areas: The unit may have been moved to storage during cleaning or room reconfiguration.
For roaming/mobile units: Check if the cart was wheeled to a different location.
If the unit is found, bring it back to the room, power it on, and connect it.
Step 4: Verify the Fix
Go to Monitoring > Units — confirm:
The unit shows as connected
Video inputs show as active with frame previews
If a case is scheduled soon, verify the room shows as ready on Monitoring > Rooms.
Step 5: Resolve the Alert
Return to the Incidents Dashboard.
Click Resolve on the incident.
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.