Flashing slowly (once per second): The server is turned off and is ready to be turned on. You can press 
the power-control button to turn on the server.
Lit: The server is turned on.
2  FPGA heartbeat LED (green)
This LED indicates power-on and power-off sequencing. 
•  LED blinking: the system is functioning properly, and no action is necessary.
•  LED not blinking: (trained technician only) replace the system board. See “System board replacement” in 
the ThinkSystem ST650 V2 Maintenance Manual.
3  XCC heartbeat LED (green) 
This LED indicates XCC heartbeat and boot process:  
•  LED blinking fast: XCC code is in the loading process.
•  LED going off momentarily: XCC code has loaded completely.
•  LED going off momentarily and then starts blinking slowing: XCC is fully operational. You can now 
press the power-control button to power on the server.
System board switches
Use this information to locate the system board switches.
Important: 
•  Read “Installation guidelines” on page 58 to ensure that you work safely.
•  Prevent exposure to static electricity, which might lead to system halt and loss of data, by keeping static- 
sensitive components in their static-protective packages until installation, and handling these devices with 
an electrostatic-discharge wrist strap or other grounding system.
•  Turn off the server before you move the switches; then, disconnect all power cords and external cables. 
Do not open your server or attempt any repair before reading and understanding the following information:
•  Any system board switch that is not shown in the illustrations in this document are reserved.
Note: If there is a clear protective sticker on the top of the switch blocks, you must remove and discard it to 
access the switches.
Chapter 2. Server components 35