Diagnostic leds – Gateway Server E-9520T User Manual
Page 83
Troubleshooting
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Diagnostic LEDs
The BIOS sends a 1-byte hex code to port 80 prior to each POST task. These
codes are displayed on eight orange LEDs, located on the system board and
available at the back of the server chassis. They can provide troubleshooting
information in the event of a system hang during POST.
POST code checkpoints
The following table shows the checkpoints, LED codes, and task description of
events that may occur during the POST portion of the BIOS:
Power LED
Identify the
power state of
the system
Front panel
Blue
Off - Power is off (or S5)
On - Power is on (or S0)
Power supply
status LED
Identify power
supply fault
Power supply
module
Green or
Red
Green (On) - Power supply
good and receiving power
Red (On) - Power supply
fault
Off - Power supply not
receiving power
LED Name
Function
Location
Color
Description
Check
point
Description
03
Disable NMI, Parity, video for EGA, and DMA controllers. Initialize BIOS,
POST, Runtime data area. Also initialize BIOS modules on POST entry and
GPNV area. Initialized CMOS as mentioned in the Kernel Variable
“wCMOSFlags.”
04
Check CMOS diagnostic byte to determine if battery power is OK and
CMOS checksum is OK. Verify CMOS checksum manually by reading
storage area. If the CMOS checksum is bad, update CMOS with power-on
default values and clear passwords. Initialize status register A.
Initialize data variables that are based on CMOS setup questions. Initialize
both the 8259 compatible PICs in the system.
05
Initialize the interrupt controller in hardware (generally PIC) and interrupt
vector table.
06
Do R/W test to CH-2 count reg. Initialize CH-0 as system timer. Install the
POSTINT1Ch handler. Enable IRQ-0 in PIC for system timer interrupt.
Trap INT1Ch vector to “POSTINT1ChHandlerBlock.”
08
Initialize the CPU. The BAT test is being done on KBC. The keyboard
controller command byte is being programmed after Auto detection of
KB/MS using AMI KB-5.
C0
Early CPU Init Start — Disable Cache - Init Local APIC
C1
Set up boot strap processor information.
C2
Set up boot strap processor for POST.
C5
Enumerate and set up application processors.