HP P27q G4 Manual

Maintenance and Service Guide
P27q G4 model
SUMMARY
This guide provides information about spare parts, removal and replacement of parts, diagnostic tests,
problem troubleshooting, and more.

© Copyright 2022 HP Development
Company, L.P.
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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 March.2022
Document Part Number:
L81900-P27q G4 -MSG-V1
Assembly part number: L81900-001
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 and side 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
Rear Cover............................................................................................................................................ 10
Power board.......................................................................................................................................... 13
Connector repair.................................................................................................................................... 14
HDMI connector CN503.............................................................................................................. 15
D-SUB connector CN101............................................................................................................ 16
Function test.......................................................................................................................................... 16
Support and troubleshooting................................................................................................................. 17

1
1 Getting started
Read this chapter to learn about safety information and where to find additional HP resources.
Important safety information
Carefully read the cautions and notes within this document to minimize the risk of personal injury to
service personnel. The cautions and notes are not exhaustive. Proper service methods are important to
the safe, reliable operation of equipment. Improper service methods can damage equipment.
The service procedures recommended and described in this service manual provide effective methods of
performing service operations. Service engineers should have prior repair knowledge and experience as
well as appropriate training for the product before performing service procedures.
●Be sure your working environment is dry and clean and meets all government safety
requirements.
●Be sure that other persons are safe while you are servicing the product.
●Do not perform any action that can cause a hazard to the customer or make the product
unsafe.
●Use proper safety devices to ensure your personal safety.
●Always use approved tools and test equipment for servicing.
●Never assume the product’s power is disconnected from the main power supply. Check that it
is disconnected before opening the product’s cabinet.
●Modules containing electrical components are sensitive to electrostatic discharge (ESD).
Follow ESD safety procedures while handling these parts.
●Some products contain more than one battery. Do not disassemble or expose a battery to high
temperatures, such as throwing into fire, or the battery may explode.
●Refer to government requirements for battery recycling or disposal.
This information provides general service information for the monitor. Adherence to the
procedures and precautions is essential for proper service.
IMPORTANT: Only trained service personnelwho are familiar with this HPproduct should perform service
or maintenance for it.Beforeperforming any service or maintenance, personnel must read the important
safety information.
IMPORTANT: You must disconnect the power cord from the power source before opening the monitor
to prevent component damage.
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
This guide describes features of the following monitors:
● 60.5 cm (23.8 in) diagonal viewable screen area with 2560 ×1440 resolution, plus full-screen support
for lower resolutions; includes custom scaling for maximum image size while preserving original aspect
ratio
● 68.6 cm (27.0 in) diagonal viewable screen area with 2560 ×1440 resolution, plus full-screen support
for lower resolutions; includes custom scaling for maximum image size while preserving original aspect
ratio
The monitor features include the following:
● Nonglare IPS panel with an LED backlight
●Wide viewing angle to allow viewing from a sitting or standing position, or when moving from side to side
● Tilt capability
●Pivot capability to rotate the monitor panel from landscape to portrait mode
●Swivel and height adjustment capabilities
●Removable stand for flexiblemonitor panel mounting solutions
●VGA video input
●One HDMI (High-DefinitionMultimedia Interface) video input (cable provided)
● Plug and Play capability, if supported by your operating system
●Security cable slot provision on rear of monitor for optional security cable
● On-screen display (OSD) adjustments in several languages for easy setup and screen optimization
● HP Display Assistant software for adjusting monitor settings and enabling the theft deterrence features
●HDCP (High-bandwidth Digital Content Protection) copy protection on all digital inputs
●Energy saver feature to meet requirements for reduced power consumption
NOTE: For safety and regulatory information, see the Product Notices provided on your optical disc, if one is
included, or in your documentation kit. To access the latest user guide, go to http://www.hp.com/support and
following the instructions to findyour product. Then select User Guides.

4
Front components
To identify the components on the front of the monitor, use this illustration and table.
Table 1-2 Front components
Control
Function
1
Menu button
Press to open the OSD menu, select a menu item from the OSD, or close the OSD
menu.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 15
You can reassign the function buttons to quickly select the most commonly
usedoperations. See Reassigning the function buttons on page 15.
3
Power button
Turns the monitor on or off.

5
Rear and side components
To identify the components on the rear of the monitor, use this illustration and table.
Table 1-1 Rear components
Component
Function
1
Power connector
Connects the power cord.
2
HDMI port
Connects the HDMI cable to a source device such as a computer
or game console.
3
VGA port
Connects the VGA cable to the source device.
4
Security cable slot
Connects an optional security cable to the monitor.

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.

7
3 Illustrated parts catalog
To identify the monitor major components, use this illustration and table.
Item
Description
Qty
1
PANEL
1
2
MIDDLE_FRAME
1
3
LENS L238W-Zat4-s4
1
4
LED BOARD
1
5
ADAPTER BOARD NA
1
6
MAIN BOARD
1
7
MAINFRAME
1
8
KEY BOARD
1
9
REAR_COVER L27W-Zat10-p12
1
10
BASE_ASS’Y L27W-Zat10-p12 NA
1
11
stand ass'y L27W-Zat10-p12 NA
1
12
BKT_VESA
2
13
INSULATING SHEET
1
14
INSULATING SHEET
1
S1
SCREW 3 4
11
S2
SCREW -- 6mm
1
S3
SCREW D3 6
5
S4
SCREW
3
S5
SCREW M4 10
4

8
How to order parts
The HP authorized repair center can purchase the power board from HP.
Power board
Description
HP spare part number
Manufacturer part
number
PSU P27q G4
N12316-001
ADPCJ1903AA2
Capacitors and connectors are available for purchase from the following EU distributors:
●RS: Capacitors | RS Components (rs-online.com)
●tme: Transfer Multisort Elektronik
●Digi-Key: Digikey Electronics
Capacitors by distributor
Component description
Location
Component
distributor
Distributor part number
EC 470UF 20% 25V 10*16
ED/EC 470UF 20% 25V
10*16 -- 1.21A ECR1EXX4
C916
Digi-Key
EEU-FM1E471
EC 470UF 20% 25V 10*16
ED/EC 470UF 20% 25V
10*16 -- 1.21A ECR1EXX4
C917
Digi-Key
RZW471M1EBK-1016S
Connectors by manufacturer
Component description
Location
identifier
Component
distributor
Distributer part
number
D-SUB
CN101
tme
HDL15-SL-B
(ADAM TECH)
HDMI
CN503
RS
SD-47151-001
(Molex)
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.
Internal and External Power Supplies are available for purchase from the following EU distributor: EET
https://www.eetgroup.com/en-eu/
NOTE: HP continually improves and changes product parts. For complete and current information
about supported parts for your product, go to https://partsurfer.hp.com/Search.aspx, 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
Rear Cover
Before removing the Rear Cover, follow these steps:
▲Prepare the monitor for disassembly. See Preparation for disassembly on page 9.
Remove the Rear Cover:
1) Remove the screws to remove the stand-base assy.
2) Use your fingers to split the left and right sides apart between the middle frame and rear case.
3) Insert the scraper bar tool into the gap between the middle frame and rear case, and then
rotate. The hook opens. Repeat the steps.

11
4) Disassemble Rear Cover.
5) Tear off the tapes. Remove 3 screws to remove the LED board.
6) Remove 11 screws to disassemble the middle frame and Panel. Disconnect the pins.

12
7) Remove the mylar.
8) Remove 5 screws to remove the Main Board and Power Board.
9) Remove 4 screws to remove the Key Board.
10) Disassemble all the boards from housing.
11) Disconnect all the wires from the board.

13
Power board
The power board part number is ADPCJ1903AA2
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 P27q G4 power board connector position is as follows:
2) Locate the part number location on the board.
Warning: After unplugging the
power supply, the capacitance
is still charged, do not touch
and discharge the capacitor.
CN902

14
Connector repair
This procedure includes HDMI, D-SUB connectors.
The connectors are on the main board (board part number CBPRNE7HPQ7).
The connectors identifiers are as follows:
Connector
Location
HDMI
CN503
D-SUB
CN101
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)
Main Board
CN101
CN503

15
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.
HDMI connector CN503
Repair the HDMI connector:
1) Use a soldering iron and a de-soldering pump to remove as much solder as possible from the
pin.
2) Use a hot air gun to melt the solder on the pins.
3) Lift the CN503 connector from the circuit board.
4) Place the new component on the circuit board. Be sure that it matches the circuit board
footprint.
5) Solder the new component.

16
D-SUB connector CN101
Repair the D-SUB connector:
1) Use a soldering iron and a de-soldering pump to remove as much solder as possible from the
pin.
2) Lift the CN101 connector from the circuit board.
3) Place the new component on the circuit board. Be sure that it matches the circuit board
footprint.
4) Solder the new component.
Function test
After repair, be sure to confirm that all functions are working.
Function test
After repair, be sure to confirm that all functions are working.
Table 4-1: Function test
Te
st item
Operating description
Tool used
HDMI test
Confirm whether image displays and sound plays
correctly on the monitor.
Computer or DVD player
DP test
Confirm whether image displays and sound plays
correctly on the monitor.
Computer or DVD player
Audio test
Change volume and balance to confirm whether
volume is smooth and loud enough.
Speaker
Table 4-1: Function test
Test item
Operating description
Tool used
HDMI test
Confirm whether image displays and sound plays
correctly on the monitor.
Computer or DVD player
D-SUB test
Confirm whether image displays and sound plays
correctly on the monitor
Computer or D-SUB player

17
Support and troubleshooting
The following table lists possible issues, the possible cause of each issue, and the recommended solutions.
Table 3-1 Common issues and solutions
Issues
Possible cause
Solution
Screen is blank or
video isflashing.
Power cord is disconnected.
Connect the power cord.
Monitor is off.
Press the monitor power button.
NOTE: If pressing the power button has no
effect, press and hold the power button for 10
seconds to disable the Power Button Lockout
feature.
Video cable is improperly
connected.
Connect the video cable properly. See
Connecting the cableson page 7 for more
information.
System is in Auto-Sleep
Mode.
Press any key on the keyboard or
move the mouse toinactivate the
screen blanking utility.
Video card is incompatible.
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 ofthe computer’s on-board video
sources.
Image appears
blurred,
indistinct, or too
dark.
Brightness setting is too
low.
Open the OSD menu, and select Brightness
to adjust the brightness scale as needed.
“Check Video Cable”
is displayed on the
screen.
Monitor video cable is
disconnected.
Connect the appropriate video signal cable
between the computer and monitor. Be sure
that the computer power is offwhile
connecting the video cable.
“Input Signal Out of
Range” is displayed
on screen.
Video resolution and/or
refresh rateare set higher
than the monitor supports.
Change the settings to a supported setting
(see Preset display resolutions on page 26).
The monitor does not
enter into a low-
power sleep state.
The monitor's power saving
control isdisabled.
Open the OSD menu and select Power,
select Auto-SleepMode, and then set
auto-sleep to On.
“OSD Lockout” is
displayed.
The monitor's OSD
Lockout functionis
enabled.
Press and hold the Menu button for 10
seconds to disable theOSD Lockout function.
“Power Button
Lockout” is
displayed.
The monitor's Power
Button Lockoutfeature is
enabled.
Press and hold the Power button for 10
seconds to unlock thepower button function.