Specifications
NTM6900 / WTM7026 Technical Reference
LED5 – CAT
When LED5 is illuminated this indicates that a catastrophic error has occurred in the system and the
motherboard’s processor(s) cannot continue to operate. The processor(s) will turn this LED on for non-
recoverable machine check errors and other internal unrecoverable errors.
LED6 - IOH Thermal Throttling LED
The IOH throttling LED is located to the right on the Intel ICH10 Southbridge. LED6 indicates the thermal
shutdown status of the IOH as illustrated below:
LED Status
Description
Off
Indicates the IOH is operating within acceptable thermal levels.
On (flashing)
Indicates the IOH is throttling down to a lower operating speed due to rising IOH
temperature.
On (solid
orange)
Indicates the IOH has reached the thermal shutdown threshold limit. The motherboard is
still operating, but a thermal shutdown may soon occur.
NOTE:
When a thermal shutdown occurs, the LED will stay on in systems using non- ATX/EPS power
supplies. The IOH will cease functioning, but power will still be applied to the motherboard. In systems with
ATX/EPS power supplies, the LED will turn off when a thermal shutdown occurs because system power is
removed via the ACPI soft control power signal S5. In this case, all motherboard LEDs will turn off;
however, stand-by power will still be present.
LED7 – PRCHT
This is the “Processor Hot” LED and it will turn on when a processor’s temperature monitoring sensor detects
that the CPU has reached its maximum safe operating temperature. This indicates that the processor’s
Thermal Control Circuit has been activated, if enabled.
POST Code LEDs
As the POST (Power On Self Test) routines are performed during boot-up, test codes are displayed on Port 80
POST Code LEDs 16, 9, 10,11,12,13,14 and 15. These LED are located in the lower left corner of the
motherboard to the right of the power status LEDs. The POST Code LEDs and are numbered from top
(position 1 = LED16) to bottom (position 8 – LED15). Refer to the board layout diagram for the exact
location of the POST code LEDs.
These POST codes may be helpful as a diagnostic tool. Specific error codes are listed in Appendix A - BIOS
Messages section of the NTM6900 Technical Reference Manual, along with a chart to interpret the LEDs into
hexadecimal format.
LED41 – S5 State
This is a green LED that when it is it on indicates that the motherboard has entered the S5 or OFF state. In
the S5, state the system is in a complete shutdown mode. The system/motherboard must be rebooted in order
to recover from the S5 state.
LED42 – S3 State
When this green LED is on it indicates that the motherboard has entered the S3 SLEEP state. Any processor
instructions, cache contents or chipset instructions that were pending when the motherboard entered the S3
state are lost. System memory is retained during the S3 sleep state.
LED47 – S4 State
If this green LED is on it indicates that the motherboard has entered the S4 or HIBERNATE state. This sleep
state consumes less power than the S3 state. A small amount of power is used to support writing any pending
data to the system’s hard drive. System memory contents are not retained in the S4 sleep state.
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