Why does the display stay all 88888's on fmc 4100?

The display showing all 88888's on an FMC 4100 typically indicates a system self-test or initialization phase. This occurs when the system is powered on or reset and is designed to confirm that the display is functioning correctly. If the display remains stuck on this screen for an extended period, it may indicate a malfunction or failure in the system that requires further troubleshooting or servicing.