HP ZBook 15 G4 Maintenance And Service Manual page 87

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
on page 77 and
help isolate the issue and indicate the next steps. For example, when the computer is running the operating
system, it may experience an issue with (4) Display, (5) I/O devices (keyboard, wireless, and so on), (6)
Storage, or (7) Mechanical components (stuck buttons, thermal shutdown, and so on).
NOTE: "Uncategorized" is used if an issue found is not listed. For example, Bluetooth is offered on certain
hardware configurations; therefore, a Bluetooth issue can be classified under "I/O Device" if needed.
Failure classification by boot-up sequence
Table 6-3 Failure classification by boot-up sequence
1. Power-on
1. No Power on page 95
2. Intermittent power-on, shutdown,
reboot on page 97
3. AC adapter issue on page 98
4. Battery not recognized, not charging
on page 99
5. Battery discharges too fast
on page 100
6. Burnt smell on page 101
a,b,c similar symptoms
Table 6-4 Failure classification by hardware devices and mechanical on page
2. POST
1.
2.
a
3.
4.
(Table 6-3 Failure classification by boot-up sequence
No video (with power)
on page 101
Blinking lights on page 102
Diagnostics error messages
on page 103
BIOS password on page 104
78). This will
3. Performance
1.
Intermittent shutdown on page 105
2.
Blue screen (BSOD) error on page 131
3. Freeze at Windows Logo (hang/lockup)
on page 108
4. Electromagnetic Interference (EMI)
on page 109
5. No wake up on page 110
6. Unresponsive on page 111
7. Slow performance on page 111
8. HP Smart Adapter warning message
on page 112
9. Incorrect time and date on page 112
General troubleshooting steps
a
b
c
77