Most cards feature a bank of LEDs that indicate the status of critical power rails and bus signals.
Indicates the presence of the main bus clock signal. If dark, the motherboard is likely not functioning at a basic level. Pci Pc Analyzer Manual
Insert the card into an available PCI or ISA expansion slot. For PCI slots, the card is keyed for correct orientation. Most cards feature a bank of LEDs that
Should flash briefly for about half a second when the system is powered on or reset. If it stays lit, the motherboard is stuck in a reset state. Pci Pc Analyzer Manual
These should remain lit constantly. If an LED is dark, it suggests a power supply failure or a short circuit on the motherboard.