Voltage Regulator (VR) Status LEDs

The VR status LEDs provide a real-time indication of how many processor VR phases are active. During normal system operation the power requirements of the processor can vary due to its power saving features. When the processor is in a low-power or idle state it requires less power to be provided by the VR. The VR responds to the lower power demand by shutting down unneeded phases thereby increasing overall power efficiency. Each VR phase has an LED connected to it that indicates when that phase is active. Figure 9 shows the location of the VR status LEDs.

Pag. 45 Intel DZ87KLT-75K Tech Spec02.pdf------------------------------------------------------------------------------------------------------------------------Board Status LEDs

11 LEDs that allow you to monitor the boards progress through the BIOS Power-on Self-Test. At initial power on, all the LEDs are off. When the BIOS starts an activity such as memory initialization, the corresponding LED starts flashing. Once the activity has completed, the LED will remain on. PositionLED Name

LED Color Supported Modes

Control Source

A

Hard Drive Activity

Blue

On/Off

Hard drive controller(s)

B

CPU Hot

Red

On/Off

Discrete circuit

C

VR Hot

Red

On/Off

Discrete circuit

D

Watch Dog Fire / Back to BIOS

Red

On/Off/Flash

BIOS

E

CPU Initialization

Green

On/Off/Flash

BIOS

F

Memory Initialization

Green

On/Off/Flash

BIOS

G

Video Initialization

Green

On/Off/Flash

BIOS

H

USB Initialization

Green

On/Off/Flash

BIOS

I

Hard Drive Initialization

Green

On/Off/Flash

BIOS

J

Option ROM Initialization

Green

On/Off/Flash

BIOS

K

Operating System Start

Green

On/Off/Flash

BIOS

Pag. 47 Intel DZ87KLT-75K Tech Spec02.pdf