System pulse LEDs

This section describes the system pulse LEDs on the system board that monitors the system power-on and power-off and boot progress.

The following LEDs are on the system board and monitor the system power-on and power-off sequencing and boot progress. For the location of these LEDs, see System-board LEDs.

CPLD heartbeat LED: If the LED flashes at 1 Hz, it is functioning properly and no action is necessary. If the LED is not flashing, replace the system board (Trained technician only).

IMM2.1 heartbeat LED: The LED status shows the following different stages of the IMM2.1 heartbeat sequencing process:
  1. When this LED is blinking fast (approximately 4 Hz), this indicates that the IMM2.1 code is in the loading process.
  2. When this LED goes off momentarily, this indicates that the IMM2.1 code has loaded completely.
  3. When this LED goes off momentarily and then starts blinking slowing (approximately 1 Hz), this indicates that IMM2.1 is fully operational. You can now press the power-control button to power on the server.
  4. (Trained technician only) If this LED does not blink within 30 seconds of connecting a power source to the server, replace the system board.
Parent topic: Diagnostic tools