B - Standby Power Indicator LED
Intel (South Lake 3) 915GV Motherboard      Show Part Numbers

Standby power indicator LED The standby power indicator LED lights to indicate that power is still present to the motherboard, even when the computer appears to be turned off.

Note: Before installing or removing any devices connected to the motherboard, turn off the computer, disconnect the power cord, and then check this LED. The LED turns off within 10 seconds after the power cord is disconnected. Failure to wait until power is completely off can result in damage to the motherboard, the device being removed, or both.