LED Blink Codes for Intel® Desktop Boards

Visible blink patterns display via the front panel power LED.

LED Blink Pattern	Sequence/Pattern	Meaning	Troubleshooting Steps
2 blinks	On-off (1.0 second each) two times, then 2.5-second pause (off). The pattern repeats once. Then the computer continues to boot.	Video error (no add-in graphics card installed)	Reseat add-in graphics card. Make sure a compatible processor is installed. For more troubleshooting steps, see: No video and two beeps during boot Intel® Processors and Boards Compatibility Tool
3 blinks	On-off (1.0 second each) three times, then 2.5-second pause (off). The pattern repeats until the computer is powered off.	Memory error	Reseat the memory. Make sure that the contacts on the memory and the socket are clean. Try removing one bank of memory modules at a time. (Some systems can require a memory module in Bank 0.) Try using memory modules from the same manufacturer with the same part number and speed. Check for a faulty memory module by trying the memory in a known good system.
16 on/off blinks	.25 seconds on, .25 seconds off, for a total of 16 blinks. Then the computer shuts down.	CPU thermal trip warning	Check that the processor heat sink/fan is properly installed. Check that the thermal interface material is sufficient and is spread evenly.
Continual blinks	Off when the update starts, then on for 0.5 seconds, then off for 0.5 seconds. The pattern repeats until the BIOS update is complete.	BIOS update in progress	This blink pattern is normal behavior. No action needed