Table 3. System pulse LEDsLED Description ActionEnclosure manager heartbeat power-on and power-off sequencing. 1. If the LED blinks at 1Hz, it isfunctioning properly and no actionis necessary.2. If the LED is not blinking, (trainedservice technician only) replacethe system board.IMM heartbeat IMM heartbeat boot process. The following steps describe thedifferent stages of the IMM heartbeatsequencing process.1. When this LED is blinking fast(approximately 4Hz), thisindicates, that the IMM code is inthe loading process.2. When this LED goes offmomentarily, this indicates thatthe IMM code has loadedcompletely.3. When this LED goes offmomentarily and then startsblinking slowing (approximately1Hz), this indicates that IMM isfully operational. You can nowpress the power-control button topower-on the server.4. If this LED does not blink within30 seconds of connecting a powersource to the server, complete thefollowing steps:a. (Trained service technicianonly) use the IMM recoveryjumper to recover the firmware(see Table 4 on page 39).b. (Trained service technicianonly) replace the systemboard.Server power featuresWhen the server is connected to power source but is not turned on, the operatingsystem does not run, and all core logic except for the service processor (theIntegrated Management Module) is shut down; however, the server can respond torequests to the service processor, such as a remote request to turn on the server.The power-on LED flashes to indicate that the server is connected to power but isnot turned on.Turning on the serverApproximately 5 seconds after the server is connected to power, one or more fansmight start running to provide cooling while the server is connected to power andthe power-on button LED will blink quickly. Approximately 20 to 40 seconds after theserver is connected to power, the power-control button becomes active (thepower-on LED will blink slowly), and one or more fans might start running to providecooling while the server is connected to power. You can turn on the server bypressing the power-control button.32 IBM System x3550 M2 Types 4198 and 7946: Installation and User’s Guide
