Maintenance and Service Guide

● Blink error code sequences continue until the computer is unplugged or the power button is pressed.
NOTE: Not all diagnostic lights and audible codes are available on all models.
The red LED blinks to represent the major error category (long blinks). The white LED blinks to represent the
minor err
or category (short blinks). For example, ‘3.5’ indicates 3 long red blinks and 5 short white blinks to
communicate the processor is not detected.
Table 7-3 Interpreting POST diagnostic front panel lights and audible codes
Category Major/minor code Description
BIOS 2.2 The main area (DXE) of BIOS has become corrupted, and there is no
r
ecovery binary image available.
2.3 The embedded controller policy requires the user to enter a key
sequence.
2.4 The embedded controller is checking or recovering the boot block.
Hardware 3.2 The embedded controller has timed out waiting for BIOS to return
from memory initialization.
3.3 The embedded controller has timed out waiting for BIOS to return
from graphics initialization.
3.4 The system board displays a power failure (crowbar).*
3.5 The processor is not detected.*
3.6 The processor does not support an enabled feature.
3.7 The access panel/top cover has been opened since last boot.
Thermal 4.2 A processor over temperature condition has been detected.*
4.3 An ambient temperature over temperature condition has been
det
ected.
4.4 An MXM over temperature condition has been detected.
System board 5.2 The embedded controller cannot nd valid rmware.
5.3 The embedded controller has timed out waiting for the BIOS.
5.4 The embedded controller has timed out waiting for BIOS to return
from system board initialization.
5.5 The embedded controller rebooted the system after a possible
lockup condition had been detected through the use of a
System Health Timer, Automated System Recovery Timer, or other
mechanism.
* Indicates hardware-triggered event; BIOS controls all other events.
90 Chapter 7 POST error messages