HP V28 4K Manual

Maintenance and Service Guide
HP V28 4K model
SUMMARY
This guide provides information about spare parts, removal and replacement of parts, diagnostic tests, problem
troubleshooting, and more.

© Copyright 2021 HP Development Company, L.P.
AMD is a trademark of Advanced Micro Devices, Inc. Bluetooth is
a trademark owned by its proprietor and used by HP Inc. under
license. NVIDIA is a trademark and/or registered trademark of
NVIDIA Corporation in the U.S. and other countries. USB Type-C
and USB-C are registered trademarks of USB Implementers
Forum. DisplayPort and the DisplayPort logo are trademarks
owned by the Video Electronics Standards Association (VESA) in
the United States and other countries.
The information contained herein is subject to change without
notice. The only warranties for HP products and services are set
forth in the express warranty statements accompanying such
products and services. Nothing herein should be construed as
constituting an additional warranty. HP shall not be liable for
technical or editorial errors or omissions contained herein.
First Edition June 2021
Document Part Number: L86478-HP V28 4K-MSG-V1
Assembly part number: L86478-001
Product notice
Only trained service personnel familiar with this product should
service it. Before performing any maintenance or service, be sure to
read “Important Safety Information”.

iii
Table of Contents
1Getting started ..............................................................................................................................................1
Important safety information...................................................................................................................1
Important service information and precautions.......................................................................................1
RoHS (2002/95/EC) requirements..........................................................................................................2
General descriptions ..............................................................................................................................2
Firmware updates...................................................................................................................................2
Before returning the repaired product to the customer..........................................................................2
2Monitor features............................................................................................................................................3
Features.................................................................................................................................................3
Front components...................................................................................................................................4
Rear components...................................................................................................................................5
Locating the serial number and product number....................................................................................6
3Illustrated parts catalog.................................................................................................................................7
How to order parts..................................................................................................................................8
4Removal and replacement procedures.........................................................................................................9
Preparation for disassembly...................................................................................................................9
RC ........................................................................................................................................................10
Power board.........................................................................................................................................15
Connector repair...................................................................................................................................16
HDMI1 connector CN501...........................................................................................................17
HDMI 2 connector CN510..........................................................................................................18
DP connector CN5301...............................................................................................................19
Audio connector CN603.............................................................................................................19
Function test.........................................................................................................................................20
Function test.........................................................................................................................................20
Support and troubleshooting................................................................................................................20
Index.....................................................................................................................................................22

1
1 Getting started
Read this chapter to learn about safety information and where to find additional HP resources.
Important safety information
A power cord is included with the monitor. If you use another cord, use only a power source and connection
appropriate for this monitor. For information about the correct power cord set to use with the monitor, see the
Product Notices provided in your documentation kit.
WARNING! To reduce the risk of electric shock or damage to the equipment:
● Plug the power cord into an AC outlet that is easily accessible at all times.
●If the power cord has a 3-pin attachment plug, plug the cord into a grounded (earthed) 3-pin outlet.
●Disconnect power from the computer by unplugging the power cord from the AC outlet. When
unplugging the power cord from the AC outlet, grasp the cord by the plug.
For your safety, do not place anything on power cords or cables. Care should be taken to route all
cords and cables connected to the monitor so that they cannot be stepped on, pulled, grabbed, or
tripped over.
To reduce the risk of serious injury, read the Safety & Comfort Guide provided with your user guides.
It describes proper workstation setup and proper posture, health, and work habits for computer
users. The Safety & Comfort Guide also provides important electrical and mechanical safety
information. The Safety & Comfort Guide is also available on the Web at http://www.hp.com/ergo.
IMPORTANT: For the protection of the monitor and the computer, connect all power cords for the
computer and its peripheral devices (such as a monitor, printer, scanner) to a surge protection device
such as a power strip or uninterruptible power supply (UPS). Not all power strips provide surge
protection; the power strip must be specificallylabeled as having this capability. Use a power strip
whose manufacturer offersa damage replacement policy so that you can replace the equipment if
surge protection fails.
Use the appropriate and correctly sized furniture designed to properly support your monitor.
WARNING! Monitors that are inappropriately situated on dressers, bookcases, shelves, desks,
speakers, chests, or carts could fall over and cause personal injury.
NOTE: This product is suitable for entertainment purposes. Consider placing the monitor in a
controlled luminousenvironment toavoid interference from surroundinglightandbrightsurfacesthat
might cause disturbing reflectionsfrom the screen.
Important service information and precautions
●Repair must be performed by professional service technicians in a repair center. End users
should not perform these procedures.
●Please note during servicing that the primary side is the high voltage area.
●This monitor meets ROHS requirements. Be sure to use lead-free solder wire when soldering.
●If you must change a capacitor, be sure to match the polarity as printed on the PCB.
●If you must replace a capacitor, make sure the specification and part number match the BOM
and location.

2
●If you must replace a capacitor, insert new parts carefully to avoid a short circuit caused by the
near pin.
●Do not get the board wet. Water and moisture can cause a short circuit that causes
malfunctions.
●To avoid damage, be sure to use lead-free solder.
●When soldering, work quickly to avoid overheating the circuit board.
●Keep the soldering iron tip clean and well tinned when replacing parts.
●After repair, perform a close inspection of the circuit board to confirm it is in good condition.
●After repair, perform a function test to confirm the power supply is working properly.
ERP Lot5 requirement
1. A professional repairer must have the technical competence to repair electronic displays and
comply with the applicable regulations for repairers of electrical equipment in the Member States
where the repairer operates. Reference to an official registration system as professional repairer,
where such a system exists in the Member States, shall be accepted as proof of compliance.
2. A professional repairer must have insurance that covers liabilities resulting from repairs,
regardless of whether required by the Member State.
RoHS (2002/95/EC) requirements
Applied to all countries that require RoHS.
The RoHS (Restriction of Hazardous Substance in Electrical and Electronic Equipment Directive) is a
legal requirement by the EU (European Union) for the global electronics industry sold in the EU and
other countries. Any electrical and electronics products launched in the market after June 2006 should
meet this RoHS requirement. Products launched in the market before June 2006 are not required to be
compliant with RoHS parts. If the original parts are not RoHS complaint, the replacement parts can be
non-ROHS complaint. If the original parts are RoHS compliant, the replacement parts MUST be RoHS
complaint.
If product service or maintenance requires replacing parts, confirm the RoHS requirement before
replacement.
General descriptions
This manual contains general information. There are two levels of service:
Level 1: Cosmetic/appearance/alignment service
Level 2: Circuit board or standard parts replacement
Firmware updates
Firmware updates for the monitor are available at support.hp.com. If no firmware is posted, the monitor
does not need a firmware update.
Before returning the repaired product to the customer
Perform an AC leakage current check on exposed metallic parts to be sure the product is safe to
operate without the potential of electrical shock. Do not use a line isolation transformer during this
check.
Measurements that are not within specified limits present a possible shock hazard. You must check and
repair the product before returning it to the customer.

3
2 Monitor features
This chapter provides an overview of the monitor’s features.
Features
The monitor includes the following features:
● 70.9 cm (27.9 in) diagonal viewable screen area with 3840 ×2160 resolution, plus full-screen support
for lower resolutions; includes custom scaling for maximum image size while preserving original aspect
ratio
● Liquid crystal display (LCD) with active matrix
●Nonglare panel with an WLED backlight
●Wide viewing angle to allow viewing from a sitting or standing position, or moving from side to side
● Tilt adjustment capability
●Removable stand for flexible monitor head mounting solutions
●HP Quick Release 2 device to quickly attach the monitor head to the stand with a simple click, and then
remove it with the convenient sliding tab release
●DisplayPort™ video input (cable included with select products)
●Two High-Definition Multimedia Interface™ (HDMI) video inputs (cable included with select products)
●Audio-out (headphone) jack
●Four on-screen display (OSD) buttons, three that you can reconfigure to quickly allow selection of the
most commonly used operations
● Plug and Play capability if supported by your operating system
●VESA® mounting bracket for attaching the monitor head to a wall-mount device or swing arm
●Support for a mounting bracket to attach the monitor to a workstation
● On-screen display (OSD) adjustments in several languages for setup and screen optimization
●Support for FreeSync™, an Adaptive-Sync technology, to reduce stuttering and tearing in games and
videos by locking the monitor’s refresh rate to the frame rate of a compatible graphics card
NOTE: Adaptive refresh rates vary by display.
●Energy saver feature to meet requirements for reduced power consumption
NOTE: For safety and regulatory information, see the Product Notices provided in your documentation kit. To
access the latest user guide, go to http://www.hp.com/support, and follow the instructions to find your product.
Then select User Guides.

4
Front components
To identify the components on the front of the monitor, use this illustration and table.
Table 1-1: Front components and their descriptions
Component
Function
(1)
Menu button
Press to open the OSD menu, select a menu item from the OSD,
or close the OSDmenu. When the OSD menu is open, the Menu
light turns on.
(2)
OSD buttons(assignable)
When the OSD menu is open, press the buttons to navigate
through the menu. The function light icons indicate the
default button functions. For a description of thesefunctions,
see Using the function buttons on page 14.
You can reassign the function buttons to quickly select the most
commonly usedoperations. See Reassigning the function buttons
on page 14.
(3)
Power button
Turns the monitor on or off.
NOTE: Be sure the master power switch on the monitor is in the
On position to turnon the monitor.
(4)
Power light
White: The monitor is on.
Amber: Monitor is in a reduced power state because of inactivity.
See Using Auto-Sleep Mode on page 15.

5
Rear components
To identify the components on the rear of the monitor, use this illustration and table.
Table 1-2: Rear components and their descriptions
Component
Function
(1)
Power connector
Connects the power cord.
(2)
VESA release button
Releases the stand from the monitor.
(3)
HDMI ports (2)
Connect the HDMI cable to a source device such as a computer or game
console.
(4)
DisplayPort connector
Connects the DisplayPort cable to a source device such as a computer or
game console.
(5)
Audio-out (headphone) jack
Connects headphones to the monitor.
CAUTION: To reduce the risk of personal injury, adjust the volume before
using headphones or earbuds. For additional safety information, see the
Product Noticesprovided in your documentation kit.
(6)
Security cable slot
Connects an optional security cable.

6
Locating the serial number and product number
The serial number and product number are located on a label on the rear of the monitor panel. You may
need these numbers when contacting HP about the monitor model.
For worldwide models (except India):

7
3 Illustrated parts catalog
To identify the monitor major components, use this illustration and table.
3
4 6 7
8
9
10
11
1
2
12
15
13
13
13
13
13
13 16
14
5
Item
Description
Qty
1
BASE_ASS’Y NA NA
1
2
stand ass'y NA NA
1
4
BEZEL L28W-Dhp3-s3
1
5
INSULATING SHEET 150*135.2*0.43
1
6
KEY_FUNCTION
1
7
KEY BOARD
1
8
LENS
1
9
MAINFRAME
1
10
ADAPTER BOARD NA
1
10
CONVERSION 715GA936*
1
11
REAR_COVER L28W-Dhp3-s3
1
12
LCD M280DGJ-L30 C5 NB INX
1
13
SCREW D3 6(MAIN BOARD/POWER
BOARD/MAINFRAME)
6
14
11REW P3 6(REAR COVER/MAINFRAME)
1
15
SCREW M4 8(POWER BOARD/MAINFRAME)
1
16
SCREW M4 10(REAR COVER/MAINFRAME)
4

8
How to order parts
The HP authorized repair center can purchase the power board from HP.
Capacitors and connectors are available for purchase from the following EU distributors:
●Farnell: Farnell UK - Electronic Components Distributor
●RS: Capacitors | RS Components (rs-online.com)
●Digi-Key: Digikey Electronics
Power board
Description
HP spare part number
Manufacturer part
number
PSU HP V28 4K
M84488-001
PLPCJF371IQA1
Capacitors by distributor
Component description
Location
Component distributor
Distributor part number
EC 680uF 20% 25V 10*20 --
-- ERS1EM681G2/EC 680UF
20% 25V 10*20 -- 4000
ECR1EXY68
C917 &
C919
Digi-Key
25ZLG680MEFC10X20
EC 680uF 20% 25V 10*20 --
-- ERS1EM681G2/EC 680UF
20% 25V 10*20 -- 4000
ECR1EXY68
C918
Digi-Key
ESY687M025AH4AA
Connectors by manufacturer
Component description
Location
identifier
Component
distributor
Distributer part
number
AUDIO
CN603
RS
913-1021(RS PRO)
HDMI
CN501/CN510
RS
SD-47151-
001(Molex)
DisplayPort
CN5301
Farnell
DP1RD20JQ1(JAE)
NOTE: Rear cover and chassis need to be modified to hold connector. Connector may need
modifications to meet functional, safety and regulatory requirements accordingly if it doesn’t match
exactly.
You can purchase cables from the HP part store at https://partsurfer.hp.com/Search.aspx.
NOTE: HP continually improves and changes product parts. For complete and current information
about supported parts for your computer, go to http://partsurfer.com, select your country or region,
and then follow the on-screen instructions.

9
4 Removal and replacement procedures
Adherence to these procedures and precautions is essential for proper service.
Preparation for disassembly
Use this information to properly prepare to disassemble and reassemble the monitor.
1) Read the “Important safety information” and “Important service information and precautions”
sections in the “Getting started” chapter of this guide.
2) Clean the room for disassembly.
3) Identify the disassembly area.
4) Check the position that the monitors are to be placed along with the number of monitors.
Prepare the area for material flow according to the disassembly layout.
5) Be sure to have the following equipment and materials:
Press fixture
Working table
Screwdriver
Knife
Gloves
Cleaning cloth
ESD protection
Scraper bar in the following dimensions:

10
RC
Before removing the RC, follow these steps:
▲Prepare the monitor for disassembly. See Preparation for disassembly on page 9.
Step
Figure
Description
1.
Preparation
Lay the
monitor on a
flat, soft and
clean surface.
2. Remove
the Stand-
base Ass’y
Push the
button the
remove the
stand-base
ass’y
3. Remove
the Rear
cover
Remove the
screws to
remove the
Rear cover.

11
4. Remove
the pin and
the screw
Remove the
pin and the
screw.
5. Remove
the tapes,
screws and
the pins
Remove the
tapes, the
screws and the
pins

12
6. Remove
the screws
Remove the
screws.
7. Remove
the screws
Remove the
screws
8. Remove
the Mylar
Remove the
Mylar

13
9. Remove
the main
board and
power board
Remove the
screws to
remove the
main board
and power
board
10. Remove
the
connectors
Remove the
connect pins
11. Remove
the screws.
Remove the
screws and the
key board.
Power Board
Main Board
Main BOARD

14
12. Remove
the screws.
Remove the
screws and
the camera.
13. The
mainframe
The mainframe
14. The panel
The panel

15
15. The
middle frame
and the key
board
The Middle
Frame and the
key boards.
Power board
The power board part number is PLPCJF371IQA1
Before removing the power board, follow these steps:
▲Prepare the monitor for disassembly. See Preparation for disassembly on page 9.
Remove the power board:
1) The HP V28 4K power board connector position is as follows:
Power Board
Warning: After unplugging the
power supply, the capacitance
is still charged, do not touch
and discharge the capacitor.

16
2) Locate the part number location on the board.
Connector repair
This procedure includes HDMI, DisplayPort and Audio connectors.
The connectors are on the main board (board part number CBPRND9H0Q1).
The connectors identifiers are as follows:
Connector
Location
HDMI 1 &2
CN501/CN510
DisplayPort
CN5301
Audio
CN603
Before repairing connectors, follow these steps:
▲Prepare the monitor for disassembly. See Preparation for disassembly on page 9.
Main Board
CN603
CN501
CN510
CN5301
Power Board

17
IMPORTANT:
• Repair Condition: Connector repair is only for out of warranty.
• Repairing must operate by professional repairers (Note) in repair center, not applicable for
end user.
• Electrostatic protection is required when component replacement is required.
• The monitor meets ROHS, please use Lead-free solder wire for soldering.
• If Connector need to replace, must check specification and part number whether match the
BOM and location.
• If connector need to replace, please insert new parts carefully because the near pin may
cause short circuit by inappropriate operate.
• DO NOT allow any liquid on the board. Water and moisture may cause short-circuit to the
electronic components and lead to malfunctions.
• The fusion point of Lead-Free solder is requested. Repairing with conventional lead wire may
cause damage.
• Work quickly to avoid overheating the circuit board as soon as you confirm the steady
soldering condition.
• Keep the soldering iron tip clean and well tinned and when replacing parts.
• A close inspection of the circuit board revealed look in good condition.
• After repaired, must connect source to each port to check Main board function is ordinary.
Note: (The requirement of professional repairers’ regulation by ERP lot5)
1) The professional repairer has the technical competence to repair electronic displays and
complies with the applicable regulations for repairers of electrical equipment in the Member
States where it operates. Reference to an official registration system as professional repairer,
where such system exists in the Member States concerned, shall be accepted as proof of
compliance with this point.
2) The professional repairer is covered by insurance covering liabilities resulting from its activity,
regardless of whether this is required by the Member State.
HDMI1 connector CN501
Repair the HDMI connector:
1) Use a soldering iron and a desoldering pump to remove as much solder as possible from the
pin.
2) Use a hot air gun to melt the solder on the pins.