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

7 Interpreting system validation diagnostic
front panel LEDs and audible codes
During the system validation phase that occurs at system startup, the BIOS validates the functionality of the
following subsystems and conditions:
● AC adapter
● System board power
● Processor failure
● BIOS corruption
● Memory failure
● Graphics failure
● System board failure
● BIOS authentication failure
If an error is detected, specic patterns of long and short blinks, accompanied by long and short beeps (where
applicable) are used to identify the error. These patterns will make up a two part code:
● Major – the category of the error
● Minor – the specic error within the category
NOTE: Single beep/blink codes are not used.
Number of long beeps/blinks Error category
1 Not used
2 BIOS
3 Hardware
4 Thermal
5 System board
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 rst 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.
76 Chapter 7 Interpreting system validation diagnostic front panel LEDs and audible codes