Boot Up Sequence; Failure Classification - HP Z VR Backpack G1 Maintenance And Service Manual

Boot up sequence

The computer performs several steps after you press the power button or restart the computer.
It is important to understand where in the boot-up sequence the symptoms occur. The following table lists the
phases of the boot-up sequence and explains the symptoms that may occur in each phase. For example, a blue
screen error (BSOD) often occurs during the performance phase.
Table 7-2 Boot-up sequence
Item
Power-on
POST (UEFI/BIOS)
Performance
(operating system)

Failure classification

Failure classification is a breakdown of different types of failures and symptoms that could occur during the
boot-up sequence. Table 3 and table 4 represent the failure classification for common notebook failures.
Table 3 categorizes failures by the boot-up sequence.
1. Power-on: Common issues are No Power, Recycle/Reboot, etc.
2. POST: Common issues are No Boot (have power), Light Flash or Diagnostics Error.
3. Performance: Common issues are Intermittent Loss of Power, Blue Screen, Hang, etc. In many cases, issues
may be identified and associated with a particular hardware (i.e., display, storage).
Table 4 categorizes failures by hardware.
4. Display
5. I/O devices (Input/Output)
6. Storage
7. Mechanical
A single symptom can be listed under different groups. For example, No Video can belong to (1) Power-on or (4)
Display; but Flickering when powered should be listed in (4) Display. Or, in another example, a blue screen can be
caused by a driver conflict in Performance (4), but it can also be caused by a defective hard drive under (6)
Storage. Therefore, failures that share similar symptoms are noted..
If possible, make a record of the failure symptom, the phase of the boot-up sequence where the failure occurs,
and the most likely location in the failure tree
and Table 7-4 Failure classification by hardware devices and mechanical on page
issue and indicate the next steps. For example, when the computer is running the operating system, it may
Procedure
After power button is pressed, the computer boots after all internal power rails (i.e., 5V, 3.3V) are stable.
Confirm that power lights are on fan is spinning.
Common issues: all lights are off; troubleshooting lights are on; does not boot; video is absent.
Power-On Self-Test (POST) verifies that hardware components (processor, hard drive, memory, etc.) are
functional. When POST is complete, the HP logo displays briefly and then disappears.
If there are errors, the computer may exhibit blinking lights and POST error messages
Common issues: lights blink, error message appears, hangs.
System boots to operating system, and Windows logo screen appears.
Common issues: hangs (lock up/freezes), blue screen, video distorted, driver conflict, slow performance, display
issue (dead pixel), I/O issue (no speaker sound), wireless/audio unavailable, noise.
See Analyze the issue on page 34
(Table 7-3 Failure classification by boot-up sequence on page 32
table below for detailed troubleshooting information).
33). This will help isolate the
General troubleshooting steps 31