Maintenance and Service Guide
Table Of Contents
- Product description
- Components
- Illustrated parts catalog
- Removal and replacement procedures preliminary requirements
- Removal and replacement procedures for Customer Self-Repair parts
- Removal and replacement procedures for authorized service provider parts
- Interpreting system validation diagnostic front panel LEDs and audible codes
- Troubleshooting guide
- Resources
- General troubleshooting steps
- Identify the issue
- Analyze the issue
- Resolve the issue
- Verify solution
- Helpful Hints
- Common issues and possible solutions
- Additional information
- Acronyms
- Blinking lights and boot error codes
- Processor not executing code
- BIOS recovery code unable to find valid BIOS recovery image
- Memory module error
- Graphics Controller Error (No Controller)
- Failure - System Board Error
- Intel Trusted Execution Technology (TXT) Error
- Sure Start unable to find valid BIOS Boot Block image
- Sure Start has identified a problem (Manual Recovery Policy Set)
- POST error messages and user actions
- Routine maintenance for performance improvement
- Common blue screen error messages
- Use Windows Debugging Tool
- Display issue: pixel anomalies
- Cable management
- Connector types
- Computer Setup (BIOS), TPM, and HP Sure Start
- Using HP PC Hardware Diagnostics
- Backing up, restoring, and recovering
- Specifications
- Power cord set requirements
- Statement of memory volatility
- Recycling
- Index

Blinking lights and boot error codes
The information below is from the white paper http://h10032.www1.hp.com/ctg/Manual/c04685655.
In some cases, when the host processor is not executing code or does not have the necessary code to drive
the display, light blink codes inform you of a problem.
Table 8-56 Blinking lights and boot error codes
Blink codes Error
Amber battery light: blinks 1 Hz continuously Embedded Controller unable to load rmware
Caps/num lock lights = 1 blink Processor not executing code
Caps/num lock lights = 2 blinks BIOS recovery code unable to nd valid BIOS recovery image
Caps/num lock lights = 3 blinks Memory module error
Caps/num lock lights = 4 blinks Graphics controller error
Caps/num lock lights = 5 blinks System board error
Caps/num lock lights = 6 blinks Intel Trusted Execution Technology (TXT) Error
Caps/num lock lights = 7 blinks Sure Start unable to nd valid BIOS Boot Block image
Caps/num lock lights = 8 blinks Sure Start has identied a problem (Manual Recovery Policy Set)
Processor not executing code
This computer has experienced a problem due to the failure of certain code to execute, resulting in a failed
startup of the processor. The issue could be related to the processor or the system board in the computer. If
the processor is socketed, be sure that the processor is seated correctly in the socket. If this error reoccurs,
refer to General troubleshooting steps on page 79.
NOTE: The computer will attempt to notify you of this problem through a series of blinking lights. When you
attempt to turn on the computer from an “O” or “Hibernated” state, lights associated with the caps lock and
num lock keys will both blink once followed by a pause, and then continue in a repeating pattern.
BIOS recovery code unable to nd valid BIOS recovery image
This computer has experienced a problem in locating a valid BIOS image, resulting in a failed startup. This
problem may be resolved by placing a clean copy of the system BIOS on a USB key or in the appropriate hard
drive directory and performing a reboot. If this error reoccurs, refer to General troubleshooting steps
on page 79.
NOTE: The computer will attempt to notify you of this problem through a series of blinking lights. When you
attempt to turn on the computer from an “O” or “Hibernated” state, lights associated with the caps lock and
num lock keys will both blink twice followed by a pause, and then continue in a repeating pattern.
Memory module error
This computer has experienced a memory initialization problem resulting in a failed startup. This issue may
be related to the memory modules in the computer. This problem may be resolved by ensuring that memory
modules are correctly inserted and seated. If this error reoccurs, a service event must be used to determine
the source of the error (memory modules or system board) and take the appropriate corrective action.
136 Chapter 8 Troubleshooting guide