Intermittent Power-On, Shutdown, Reboot - HP ZBook Studio G4 Maintenance And Service Manual

Intermittent power-on, shutdown, reboot

Symptoms
● Does not always turn on
● Intermittently hangs
Intermittently shuts down
●
Spontaneously reboots
●
The sections below are intended for authorized service providers/technicians.
See "Overview of How to Troubleshoot Problems When a Computer Does Not Start Up
or Boot Properly" at http://h20566.www2.hp.com/hpsc/doc/public/display?
docLocale=en_US&docId=emr_na-c01443371
Possible causes
Electrical short, fluctuating power source, unstable power rails, loose connections, bent
pins, stray wires, dust, obvious damage, nearly faulty parts (bulging/leaking capacitor).
Potentially will turn into a no power issue soon
Troubleshooting steps
1. Make sure drivers are updated.
2. Visually check power ports on both AC adapter and computer sides.
3. Inspect power sources:
a. Verify AC adapter working correctly. Use a confirmed working adapter to test.
b. Verify that battery is not depleted while system is in Sleep state. Test with a
confirmed working battery.
1. Follow actions in No Power on page
a. Be sure that AC adapter has correct DC voltage.
b. Verify battery - test with a confirmed working battery.
c. Verify that power button is not stuck.
d. Verify that power connector is not loose.
e. Verify that Power Good LEDs are solid.
f. Remedy loose connections and reseat major components (processor, memory,
GPU, hard drive/solid-state drive, etc).
2. Perform visual check for loose connections, bent pins, stray wires, dust, nearly
faulty parts (bulging/leaking capacitor).
3. Test essential hardware configuration
on page 80)
a. If system boots, reinstall nonessential hardware one component at a time to
isolate issue.
b. If system does not boot, replace essential hardware with verified working
parts, one component at a time. If system still does not boot, replace system
board.
(No Power on page 85).
85.
(11. Test with minimum configuration
Common issues and possible solutions 87