Function Test; Support And Troubleshooting - HP V28 4K Maintenance And Service Manual

4) Solder the new component.

Function test

After repair, be sure to confirm that all functions are working.
Table 4-1:
Test item Te
Function test
st item
HDMI test
HDMI test
DP test
DP test
Table 4-1:
Audio test
Audio test

Support and troubleshooting

The following table lists possible problems, the possible cause or each problem, and the
recommended solutions.
Table 4-2:
Problem
Screen is blank or
video is flashing.
Image appears
blurred, indistinct, or
too dark.
"Check Video Cable"
is displayed on the
screen.
"Input Signal Out of
Range" is displayed
on screen.
The monitor does not
enter into a low-power
sleep state.
"OSD Lockout" is
20
Function test
Operating description Operating description
Confirm whether image displays and sound plays
After repair, be sure to confirm that all functions are working.
correctly on the monitor.
Confirm whether image displays and sound plays
correctly on the monitor.
Confirm whether image displays and sound plays
correctly on the monitor.
Confirm whether image displays and sound plays
Function test
correctly on the monitor.
Change volume and balance to confirm whether
volume is smooth and loud enough.
Change volume and balance to confirm whether
volume is smooth and loud enough.
Solving common problems
Possible cause
Power cord is disconnected.
Monitor is off.
Video cable is improperly connected.
System is in Auto-Sleep Mode.
Video card is incompatible.
Brightness setting is too low.
Monitor video cable is disconnected.
Video resolution and/or refresh rate are set
higher than the monitor supports.
The monitor's power saving control is
disabled.
The monitor's OSD Lockout function is
Tool used Tool used
Computer or DVD
player
Computer or DVD player
Computer or DVD
player
Computer or DVD player
Speaker
Speaker
Solution
Connect the power cord.
Press the monitor power button.
NOTE: If pressing the power button has no
effect, press and hold the power button
for 10 sec to disable the Power Button
Lockout feature.
Connect the video cable properly. For
more information, see Connecting the
cables on page 8.
Press any key on the keyboard or move
the mouse to inactivate the screen
blanking utility.
Open the OSD menu and select the
Input menu. Set Auto- Switch Input
to Off and manually select the input.
or
Replace the video card or connect the
video cable to one of the computer's on-
board video sources.
Open the OSD menu, and select
Brightness to adjust the brightness scale
as needed.
Connect the appropriate video signal
cable between the computer and monitor.
Be sure that the computer power is off
while connecting the video cable.
Change the settings to a supported
setting (see Preset display resolutions on
page 22).
Open the OSD menu and select Power,
select Auto-Sleep Mode, and then set
auto-sleep to On.
Press and hold the Menu button for 10