HP ProDesk 400 G4 Maintenance And Service Manual page 93

Number of long beeps/blinks
4
5
Patterns of blink/beep codes are determined by using the following parameters:
● 1 second pause occurs after the last major blink.
● 2 second pause occurs after the last minor blink.
● Beep error code sequences occur for the first 5 iterations of the pattern and then stop.
● 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 error category (short blinks). For example, '3.5' indicates 3 long red blinks and 5 short white blinks to
communicate the processor is not detected.
Category
BIOS
Hardware
Thermal
System board
* Indicates hardware triggered event; all other events are controlled by the BIOS.
Error category
Thermal
System board
Major/minor code Description
2.2 The main area (DXE) of BIOS has become corrupted and there is no recovery
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.
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.
4.2 A processor over temperature condition has been detected.*
4.3 An ambient temperature over temperature condition has been detected.
4.4 An MXM over temperature condition has been detected.
5.2 The embedded controller cannot find valid firmware.
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.
Interpreting system validation diagnostic front panel LEDs and audible codes 85