Troubleshooting steps for a faulty Sharp/NEC LED wall

1. Confirm the Problem

• Pixel is black, stuck on one colour, dim, or flickering.
• If it shows up the same on all test colours, this indicates a hardware issue.

2. Quick Checks

• Change the video source or cable
• If the pixel stays bad then this will not be a signal problem

3. What It Means

• Most likely a failed LED pixel
• Often limited to one panel/module

4. What to Do

The best fix would be to replace the affected LED module.
Please note that a small number of bad pixels may be considered normal