Video · Practical guide
Black screen or no picture at an event: trace the video signal
If the operator's monitor has a picture but the audience screen is black, compare the two signal paths. Find the last point where the correct source is visible, then check the next section. This guide helps you organize the tests; use the installed equipment's manual for specific controls and supported formats.
Identify what disappeared and which output is affected
No Signal is different from a black or frozen picture. Record the exact message, time and affected destination. Compare the room screen, live stream and control monitor. If you are recording, check the file too: a picture on the recorder's monitor does not confirm what was saved.
If the event is running, notify the show director and use the agreed backup. Schedule any test that could interrupt another output with the operators. The conference continuity guide (Spanish) helps you prepare these arrangements.
| Observation | What to record | Next question |
|---|---|---|
| The destination displays No Signal | Exact message, selected input and time | What is reaching this point through the current signal path? |
| The picture is black | Source status, selected source and control-monitor view | Where was the expected content last visible? |
| The picture is frozen | Content that should be changing and controls that still respond | Has the picture also stopped at earlier points? |
| Only part of the screen is missing | Affected area and comparison with the remaining areas | Which components do they share, and where do their paths separate? |
Map the signal path and mark the last correct picture
Write down the equipment actually connected: computer or camera, adapters, distribution, switcher, processor and destination, as applicable. Identify the input and output at each stage. Draw recording and streaming branches separately.
Mark where you checked the same source and how you viewed it. The section between the last correct picture and the next point without it needs investigation; you have not yet identified a failed component. Include the cables, connections, equipment and routing selections in that section.
Check which output the computer is using
Confirm which file the application is playing, what its internal preview shows and which output is assigned. Record those three separately, then check the show destination. Keep the initial configuration so you can restore it after the test.
In Resolume, Output Setup explains how to configure the system displays before assigning an output. Identify Displays identifies the numbered destinations, and Show Test Card displays resolution, time and a moving line. Agree when to show these tests, then return to the content. For multiple outputs, see the Resolume guides.
Use a test monitor with a known input and format
Agree with the technician where to connect the test monitor, and identify the source, input, cable and format. Replacing the screen with another receiver changes part of the signal path: a working test monitor does not prove that the original connection is good.
The Video Assist 12G HDR guide (Spanish) explains the input-selection and format-display controls. Also note whether the expected content is visible at that point, then check the next output and the actual destination.
Compare the reported input format with the picture
Compare the full format reported by the input with the formats that model supports. If the equipment does not display it, note that limitation. Avoid changing resolution or frame rate on several devices at once: you would lose track of which adjustment produced the result.
The guides to PT-RZ120 STATUS (Spanish) and the VX1000 internal test pattern (Spanish) explain their controls and limits. Record where each test originates: a test that starts inside the processor leaves the upstream equipment unchecked.
Check the source selected for the audience output
Ask the operator to identify the source feeding the affected output. Note which source appears on the control monitor and which is sent to the audience. If those paths differ, check both before blaming the screen.
Record the switcher, processor and destination settings without changing several at once. For an ATEM Mini Pro, the USB and HDMI output guide (Spanish) covers the documented configuration. The exact settings depend on the model; a picture recovered during testing still needs checking with the show selection restored.
Change one variable and record the result
Decide what you are comparing and why. For example, keep the source, format and receiver unchanged and try another identified, compatible cable. Record the previous state, the change and what happened. If another connection or setting also changed, include it in the test record.
An improvement helps narrow the diagnosis. Before closing the issue, check whether the symptom returns and what remains different from the original setup. Use the diagnostic worksheet to separate observations, possible causes and checks still to be made.
Return to show content and check every destination
Remove test patterns and test material as agreed with the operators. Confirm the source, file and playback position that should return to program. Check picture and sound if the segment uses both, and record what reached each intended destination. If recording is part of the job, open the test recording; watching its monitor leaves the file itself unchecked.
Observe the system with representative content during an agreed test window. If the fault was intermittent, record how long the test ran and under what conditions. A still image displayed for a few seconds does not confirm that the whole segment works or rule out the problem returning.
Prepare a report another technician can follow
Share the worksheet with the signal path, models, connections, formats, time of the symptom and tests performed. Attach screenshots or a short video showing the problem, and note what remains unchecked. Distinguish the observed recovery from a confirmed cause.
For an issue involving Resolume, Reporting a Bug asks for reproducible steps, actual and expected results, the version including revision, and the platform. Include relevant evidence; the manual points to Preferences → Feedback to send the log. Prepare the support information for the affected configuration without assuming that a black screen proves a software fault.
Frequently asked questions
Do a black picture and No Signal indicate the same fault?
They are different observations, and neither identifies the cause on its own. Record the exact message and selected input. Then follow the same source from the last point showing the expected content to the next point without a picture.
If the laptop works on a monitor, have I checked the LED wall?
No. You have only checked the connection and monitor used in that test. Now follow the path to the LED wall, including its cables, equipment, inputs and outputs.
Does the last point with a picture identify the failed device?
It identifies the section that still needs checking. Between that point and the next there may be cables, connections, an input selection or equipment. Check that section before attributing the fault to a component.
Should I change the cable, resolution and input together?
Avoid doing that: if the picture returns, you will not know which change restored it. Test one variable at a time and keep the initial settings. If a test requires several changes, record them as a combination.
How do I document a frozen picture when the equipment still detects a signal?
Note which part of the content should be moving or changing. Compare that same source at the available points, recording where the picture stopped updating and which controls still responded. This helps narrow down the section that needs checking.
Can I run the test during a presentation?
Agree a test window with show direction and the operators for anything that could affect the program. During the session, use the planned backup and record the symptom.
What should I check after the show picture returns?
Return to the event content and check the selected source and every destination through the actual signal path. If the fault was intermittent, record the observation time and conditions. The result describes that test; it does not rule out a recurrence.
What does GLMedia need to investigate a screen with no picture?
The video signal path, models, ports, formats and affected destination. Include the message or screenshot, when the fault occurred, prior changes, tests performed and the result at each point.