Customer question: The display works, but the image is unstable or has trails. What should I check?
English explanation
Describe the symptom precisely before changing parts. Flicker may be visible to the eye or only to a camera. Ghosting, trailing, colour cast, scan artefacts and pixel misalignment have different possible causes. Record the fault area, content, brightness, camera settings, time of occurrence and whether the issue appears during pure-colour and grayscale tests. Check the source and input format, then the processor output and signal link. Review cascade direction, port loading, fiber/SFP or RJ45 condition and power stability. Next verify the project-specific receiving-card configuration, scan mode, data group, driver support, refresh and brightness settings. Inspect HUB boards and ribbon cables only after power is isolated. If the problem is fixed at one cabinet boundary, the local cabinet path is more likely; if it moves with content or input, the source or processor needs attention. Use one known-good cabinet or cable for comparison. Do not change brightness, refresh, configuration and firmware together. A phone video with bands is not sufficient proof of a low-refresh fault; camera shutter and rolling shutter can create artefacts.
Service boundary
Firmware changes require exact hardware confirmation. Do not downgrade a working controller or load another project’s configuration as a trial. —
