Blinking Lights; Diagnostics Error Messages - HP ZBook 15u Maintenance And Service Manual

Blinking lights

Table 8-16 Issues, possible causes, and fixes
Items
Symptoms
Lights blink on keyboard
lock/num lock keys
Note

Diagnostics error messages

Table 8-17 Issues, possible causes, and fixes
Items
Symptoms
Computer has power
●
POST error message displays
●
(Windows logo has not yet
appeared)
Procedures
Possible causes
caps Blinking lights on startup usually indicate a problem with basic functionality of a critical
component (processor, BIOS, graphics cards, memory, etc.) due to loose connection,
defective parts, or recently added parts.
Troubleshooting steps
1. Check for any blink patterns. Count the number of blinks in a sequence, followed by a
pause for a few seconds.
2. See Status, Blinking Lights, and Error Message
troubleshooting lights, and POST error messages on page
3. If internal hardware components (memory, hard drive, etc.) have been recently added, a
component may not be connected properly. Remove and reseat new components
Reseat cables and connections on page
Since the display may not be functional, lights are used to indicate an error.
Procedures
Possible causes
Diagnostic error messages indicate a problem. There may be a problem with the instruction
being sent from the BIOS to a hardware component (e.g., keyboard failures), or
incompatible hardware. Can usually be resolved by installing updated firmware for the
component.
Troubleshooting steps
1. See 7. Status lights, blinking light codes, troubleshooting lights, and POST error
messages on page 87
shown below.
2. If there is power, you may be able to access BIOS. Reset BIOS to its default condition.
(9. Soft reset (Default Settings) on page
3. Restore hardware to its original condition (i.e., bootable solid-state drive instead of
hard drive).
4. Reseat suspected components and verify connection.
(7. Status lights, blinking light codes,
90) one at a time.
for corrective actions. An example of a POST error message is
90)
Common issues and possible solutions 103
87) for corrective actions.
(10.