HP Z VR Backpack G1 - Boot up Sequence; Failure Classification

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 Procedure
Power-on After power button is pressed, the computer boots after all internal power rails (i.e., 5V, 3.3V) are stable.
Conrm that power lights are on fan is spinning.
Common issues: all lights are o; troubleshooting lights are on; does not boot; video is absent.
POST (UEFI/BIOS) Power-On Self-Test (POST) veries that hardware components (processor, hard drive, memory, etc.) are
functional. When POST is complete, the HP logo displays briey 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.
Performance
(operating system)
System boots to operating system, and Windows logo screen appears.
Common issues: hangs (lock up/freezes), blue screen, video distorted, driver conict, slow performance, display
issue (dead pixel), I/O issue (no speaker sound), wireless/audio unavailable, noise.
See Analyze the issue on page 34 table below for detailed troubleshooting information).
Failure classication
Failure classication is a breakdown of dierent types of failures and symptoms that could occur during the
boot-up sequence. Table 3 and table 4 represent the failure classication 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 identied 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 dierent 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 conict 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 (Table 7-3 Failure classication by boot-up sequence on page 32
and Table 7-4 Failure classication by hardware devices and mechanical on page 33). This will help isolate the
issue and indicate the next steps. For example, when the computer is running the operating system, it may
General troubleshooting steps 31