Intel DZ77BH-55K, Specification, Page: 40 / 100

Intel Desktop Board DZ77BH-55K Technical Product Specification
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1.11.2.10 Power Supervisor
The Power Supervisor actively monitors the input voltages from the power supply and
protects the board and any attached peripherals from electrical overstress and possible
physical damage. The Power Supervisor will activate if it detects the power supply
voltage rails have deviated outside the current ATX power supply specification and safe
operating levels.
If the Power Supervisor detects an out of spec voltage, the following will happen:
1.
The board will be powered down immediately to protect circuits from electrical
overstress and possible physical damage.
2. A red warning LED (see Figure 1, W) on the board will activate as a visual cue.
3. During the next power on, a message will be displayed on the screen to notify the
user that the power supply voltage rails have deviated outside the current ATX
power supply specification and safe operating levels.
4. A message will be added to the BIOS Event Log for each event that takes place
until the BIOS Event Log is cleared.
1.11.2.11 +5 V Standby Power Indicator LED
The +5 V standby power indicator LED shows that power is still present even when the
computer appears to be off. Figure 9 shows the location of the standby power LED.
CAUTION
If AC power has been switched off and the standby power indicator is still lit,
disconnect the power cord before installing or removing any devices connected to the
board. Failure to do so could damage the board and any attached devices.
Figure 7. Location of the Standby Power LED