Output Not Displaying

Last updated 9 April 2026

Your physical output device (projector, display, or LED wall) shows a black screen, no signal, or the wrong content. This guide walks through the most common causes in order of likelihood.

Before you start

  • Confirm the physical device is powered on and connected to the correct GPU port on the server.

  • Check for a signal lock indicator on the device itself (separate from Backstage).

  • Open the Outputs panel in Backstage and verify the GPU output port appears in the list.

Symptom: Black screen — output shows nothing at all

Check 1: Output is turned off

Every GPU output has a Turn on checkbox. If it is unchecked, Backstage renders nothing to that port.

  1. Select the GPU output in the Outputs panel.

  2. In the Inspector, expand Test & Debug.

  3. Confirm Turn on is checked.

Check 2: No Projector or Display routed to the output

A GPU output only renders content when at least one Projector or Display is routed to it via the Video Routing matrix. Without this routing, nothing appears on the port.

  1. Open the Video Routing window.

  2. Find the column for your GPU output.

  3. Find the row for the Projector or Display you want to send to that output and click the cell to place a blue checkmark.

Check 3: Projector or Display not in a Group

Every Projector and Display must belong to a Group. Groups own the render loop — objects outside a Group are not rendered.

  1. Open the Scene Objects panel and confirm your Projector or Display is nested under a Group in the tree.

  2. If the object is not inside a Group, drag it into an existing Group or create a new one using the + icon and move the object into it.

Check 4: No Sequence playing, or Sequence targeting the wrong Surface

Content reaches outputs through Sequences. Each Video Channel in a Sequence has a Destination that targets one or more Surfaces. If no Sequence is playing, or if the active Sequence targets a different Surface than the one your Projector is looking at, the output will be black.

  1. Open the Sequencer and confirm a Sequence is playing.

  2. Select the Video Channel inside that Sequence. In the Inspector, check the Destination section and confirm it includes the Surface your Projector is projecting onto.

  3. If the Destination is empty or points to a different Surface, update it to match.

Symptom: "No signal" on the physical device

Check 1: Output not recognized by Windows

Backstage renders to GPU outputs that Windows recognizes as connected displays. If Windows does not see the display, Backstage cannot output to it.

  1. Open Windows Display Settings (right-click desktop → Display settings) and confirm the display appears in the layout.

  2. If it does not appear, check cables and adapters. For headless or EDID emulator setups, ensure the EDID is being read correctly by the GPU.

Check 2: Resolution or refresh rate mismatch

If the GPU output is configured at a resolution or refresh rate the physical device does not support, the device will report no signal.

  1. Select the GPU output in the Outputs panel and note the Output Resolution in the Inspector.

  2. Confirm this resolution and refresh rate match what your physical device supports.

  3. Cross-check in the NVIDIA Control Panel (or AMD equivalent) and adjust if necessary.

Symptom: Wrong content on the output

Check 1: Wrong Projector routed to this output

If multiple Projectors exist in the scene, the wrong one may be routed to this GPU output.

  1. Open the Video Routing window and check which Projector has a blue checkmark in the column for this output.

  2. Remove the incorrect routing and route the correct Projector.

Check 2: Test image active

The Test & Debug section can display test images (white bar, solid color, debug views) that override normal content.

  1. Select the output and expand Test & Debug in the Inspector.

  2. Set the test image dropdown back to None.

Check 3: Blend mask blocking content

A fully opaque black blend mask will make the entire output appear black even when content is playing correctly.

  1. Select the output and expand the Blend Mask section in the Inspector.

  2. If Enable Blend Mask is checked, temporarily uncheck it to confirm it is the cause. Verify the mask file is correct if it needs to remain active.

Options explained

Option

Where to find it

What it does

Turn on

Output Inspector → Test & Debug

Enables or disables rendering for this specific output.

Video Routing checkmark

Video Routing window

Routes a Projector or Display to a specific GPU output port.

Group membership

Scene Objects panel (tree hierarchy)

Determines which render loop processes the Projector or Display.

Channel Destination

Sequencer → select Channel → Inspector

Sets which Surface + Mapping a Video Channel renders content to.

Test image

Output Inspector → Test & Debug

Overrides output with a diagnostic image (white bar, solid color, etc.).

Blend Mask

Output Inspector → Blend Mask

Applies a PNG mask image over the output. A fully black mask makes the output appear black.

Common Mistakes

  • Projector added to the scene but not routed to an output. Adding a Projector to the scene and pointing it at a Surface is not enough. You must also route it to a GPU output via the Video Routing matrix. Without the routing, the Projector renders internally but the result never reaches a physical port.

  • Video Channel Destination points to the wrong Surface. If you have multiple Surfaces in the scene, the Channel may be targeting a Surface that a different Projector covers. Always verify the Destination in the Channel Inspector matches the Surface your output's Projector is aimed at.

  • Output disabled by a Node Editor graph. The Node Editor can programmatically enable or disable video outputs. If a previous show control graph disabled an output and was not reset, the output stays off even though the Inspector does not make this obvious. Check your graph for any nodes controlling output enable state.

Tips

  • Use the Output View panel to see what Backstage is rendering to a selected output without looking at the physical device. If the Output View shows content but the device is black, the issue is physical (cable, EDID, device settings).

  • The white bar test image in Test & Debug sweeps across the output. Use it to quickly verify the physical connection is working before troubleshooting content or routing issues.

  • When diagnosing multi-projector setups, temporarily route a single Projector to a single output and confirm it works end-to-end before rebuilding the full routing matrix.

  • If content appears but is geometrically wrong (warped, scaled incorrectly), the routing and rendering pipeline is working. Switch focus to Output Warping and Projector properties.

  • GPU Output — reference for GPU output properties and configuration

  • Outputs — overview of all output types in Backstage

  • Group — how Groups organise rendering in the scene

  • Settings — global Backstage settings

  • Performance Issues — troubleshooting dropped frames, low frame rate, and GPU bottlenecks