Dell S2421HGFB Instructions for use

Simplified Service Manual–S2421HGFB
Version: 01
Date:2021/03/04

Content Index
1. General Safety Instructions ....................................................................................... 3
1.1 SAFETY: General Safety ...................................................................................... 3
1.2 SAFETY: General Power Safety ........................................................................... 5
2. Exploded view diagram with list of items ................................................................. 6
3. Wiring connectivity diagram ...................................................................................... 7
4. Disassembly and Assembly Procedures .................................................................. 8
4.1 Disassembly SOP ................................................................................................. 8
4.2 Assembly SOP .....................................................................................................11
5. Trouble shooting instructions ................................................................................. 14

1. General Safety Instructions
Use the following safety guidelines to help ensure your own personal safety and to help protect your
equipment and working environment from potential damage.
NOTE: In this section, equipment refers to monitors.
IMPORTANT NOTICE FOR USE IN HEALTHCARE ENVIRONMENTS:
Dell products are not medical devices and are not listed under UL or IEC 60601 (or equivalent). As a
result, they must not be used within 6 feet of a patient or in a manner that directly or indirectly
contacts a patient
1.1 SAFETY: General Safety
WARNING: To prevent the spread of fire, keep candles or other open flames away from this product
at all times.
When setting up the equipment for use:
Place the equipment on a hard, level surface. Leave 10.2 cm (4 in) minimum of clearance on
all vented sides of the computer to permit the airflow required for proper ventilation.
Restricting airflow can damage the computer or cause a fire.
Do not stack equipment or place equipment so close together that it is subject to
recalculated or preheated air.
NOTE: Review the weight limits referenced in your computer documentation before placing
a monitor or other devices on top of your computer.
Ensure that nothing rests on your equipment's cables and that the cables are not located
where they can be stepped on or tripped over.
Ensure that all cables are connected to the appropriate connectors. Some connectors have
a similar appearance and may be easily confused (for example, do not plug a telephone
cable into the network connector).
Do not place your equipment in a closed-in wall unit or on a bed, sofa, or rug.
Keep your device away from radiators and heat sources.
Keep your equipment away from extremely hot or cold temperatures to ensure that it is used
within the specified operating range.
Do not push any objects into the air vents or openings of your equipment. Doing so can
cause fire or electric shock by shorting out interior components.
Avoid placing loose papers underneath your device. Do not place your device in a closed-in
wall unit, or on a soft, fabric surface such as a bed, sofa, carpet, or a rug.

When operating your equipment:
Do not use your equipment in a wet environment, for example, near a bath tub, sink, or
swimming pool or in a wet basement.
Do not use AC powered equipment during an electrical storm. Battery powered devices may
be used if all cables have been disconnected.
Do not spill food or liquids on your equipment.
Before you clean your equipment, disconnect it from the electrical outlet. Clean your device
with a soft cloth dampened with water. Do not use liquids or aerosol cleaners, which may
contain flammable substances.
Clean the monitor display with a soft, clean cloth and water. Apply the water to the cloth,
then stroke the cloth across the display in one direction, moving from the top of the display
to the bottom. Remove moisture from the display quickly and keep the display dry.
Long-term exposure to moisture can damage the display. Do not use a commercial window
cleaner to clean your display.
If your equipment does not operate normally - in particular, if there are any unusual sounds
or smells coming from it - unplug it immediately and contact an authorized dealer or service
center.
Protecting Against Electrostatic Discharge
Electrostatic discharge (ESD) events can harm electronic components inside your equipment. Under
certain conditions, ESD may build up on your body or an object, such as a peripheral, and then
discharge into another object, such as your computer. To prevent ESD damage, you should
discharge static electricity from your body before you interact with any of your equipment’s internal
electronic components, such as a memory module. You can protect against ESD by touching a metal
grounded object (such as an unpainted metal surface on your computer’s I/O panel) before you
interact with anything electronic. When connecting a peripheral (including handheld digital assistants)
to your equipment, you should always ground both yourself and the peripheral before connecting it. In
addition, as you work inside the equipment, periodically discharge any static charge your body may
have accumulated.
You can also take the following steps to prevent damage from electrostatic discharge:
When unpacking a static-sensitive component from its shipping carton, do not remove the
component from the antistatic packing material until you are ready to install the component.
Just before un wrapping the antistatic package, be sure to discharge static electricity from
your body.
When transporting a sensitive component, first place it in an antistatic container or
packaging.
Handle all electrostatic sensitive components in a static-safe area. If possible, use antistatic
floor pads and work bench pads.

1.2 SAFETY: General Power Safety
Observe the following guidelines when connecting your equipment to a power source:
Check the voltage rating before you connect the equipment to an electrical outlet to ensure
that the required voltage and frequency match the available power source.
Do not plug the equipment power cables into an electrical outlet if the power cable is
damaged
Norway and Sweden: If this product is provided with a 3-prong power cable, connect the
power cable to a grounded electrical outlet only.
If you use an extension power cable, ensure that the total ampere rating of the products
plugged in to the extension power cable does not exceed the ampere rating of the extension
cable.
If you must use an extension cable or power strip, ensure the extension cable or power strip
is connected to a wall power outlet and not to another extension cable or power strip. The
extension cable or power strip must be designed for grounded plugs and plugged into a
grounded wall outlet.
If you are using a multiple-outlet power strip, use caution when plugging the power cable into
the power strip. Some power strips may allow you to insert a plug incorrectly. Incorrect
insertion of the power plug could result in permanent damage to your equipment, as well as
risk of electric shock and/or fire. Ensure that the ground prong of the power plug is inserted
into the mating ground contact of the power strip.
Be sure to grasp the plug, not the cable, when disconnecting equipment from an electric
socket.
If your equipment uses an AC adapter:
Use only the Dell provided AC adapter approved for use with this device. Use of another AC
adapter may cause a fire or explosion.
NOTE: Refer to your system rating label for information on the proper adapter model
approved for use with your device.
Place the AC adapter in a ventilated area, such as a desk top or on the floor, when you use
it to run the computer or to charge the battery. Do not cover the AC adapter with papers or
other items that will reduce cooling; also, do not use the AC adapter inside a carrying case.
The AC adapter may become hot during normal operation of your computer. Use care when
handling the adapter during or immediately after operation.
It is recommended that you lay the adapter on the floor or desk so that the green light is
visible. This will alert you if the adapter should accidentally go off due to external effects. If
for any reason the green light goes off, disconnect the AC power cord from the wall for a
period of ten seconds, and then reconnect the power cord.
Japan Only: Use only the Dell-provided AC power cable with the AC adapter. Use of any
other power cable may damage the device or AC adapter or may present risk of fire or
electric shock.

2. Exploded view diagram with list of items
Item
Description
Q'ty
1 ASSY BZL CHIN 1
2 Panel 1
3
MF
1
4 MYLAR PWR 1
5
PCBA I/F BD
1
6 PCBA SPS BD 1
7
ASSY SHD MAIN
1
8
ASSY RC
1
9 ASSY CLMN 1
10 ASSY BASE 1
11 PCBA CTRL BD 1
12 PCBA CTRL+KEY BD 1
13 BTN-PWR 1
14 PCBA CTL LENS BD 1
1
5
Power cable
1
16 HDMI cable 1
15
16

- 7 -
3. Wiring connectivity diagram
FFC 1 FFC 2
FFC 3
FFC 4
Wire 1

- 8 -
4. Disassembly and Assembly Procedures
4.1 Disassembly SOP
Preparation before disassemble
1. Clean the room for disassemble
2. Identify the area for monitor
3. Check the position that the monitors be placed and the quantity of the monitor; prepare the area for
material flow; according to the actual condition plan the disassemble layout
4. Prepare the implement, equipment, material as bellow:
1) Working table
2) Philips-head screwdriver
3) Glove
4) Cleaning cloth
5) ESD protection
I
tem
P
icture
Operation
Tool
Notes
1
To remove the stand:
1. Place the monitor
on a soft cloth or
cushion.
2. Press and hold the
stand release button
3. Lift the stand up and
away from the
monitor.
2
1. Unlock 4 RC screws
Philips-head
screwdriver
(Torsion of
RC screw:
8~10Kg)

- 9 -
3
1. Use hands or
scraper bar to
disassemble Rear
Cover from monitor
Notice the disassembly
order:
Top Side=>Right/ Left
Side=>Bottom Side
2. Remove CTRL BD
FFC wire from I/F
BD and remove all
tapes from panel
Scraper bar
4
1. Remove PWR BTN
BD FFC wire from
I/F BD
2. Unlock 4 screws on
Main SHD
Philips-head
screwdriver
(Torsion of
screw:
4.5±0.5Kg)
5
1. Remove backlight
wire from SPS BD
and remove all
tapes from panel
2. Remove AL foil and
yellow tape from
panel
3. Remove two LVDS
FFC cable from
panel

- 10 -
6
1. Remove Mylar from
SPS BD
7
1. Unlock 8 PCBA
screws
Philips-head
screwdriver
(Torsion of
screw:
8.5±1.0kg)
8
1. Disassemble I/F BD
from Main SHD and
remove SPS BD
wire from I/F BD
2. Remove two LVDS
FFC cable from I/F
BD
3. Disassemble SPS
BD from Main SHD

- 11 -
4.2 Assembly SOP
Preparation before assemble
1. Clean the room for work
2. Identify the area for material
3. Prepare the implement, equipment, material as bellow:
1) Working table
2) Philips-head screwdriver
3) Glove
4) Cleaning cloth
ESD protection
Item
Picture
Operation
Tools
Notes
1
1. Assemble SPS BD to Main SHD
2. Insert two LVDS FFC cables to
I/F BD
3. Insert SPS BD wire to I/F BD and
assemble I/F BD to Main SHD
4. Lock 8 PCBA screws
Philips-
head
screwdriver
(Torsion of
screw:
8.5±1.0kg)
2
1. Assemble Mylar to SPS BD

- 12 -
3
1. Insert two FFC LVDS cable to
panel
2. Paste 1 yellow tape and then
paste 1 AL foil on yellow tapes
3. Insert Backli ht wire to SPS BD
and paste 1 tape to fixed
Backli ht wire on panel
4
1. Locate Main SHD to panel and
lock 4 screws
2. Insert PWR BTN BD wire to I/F
BD
Philips-
head
screwdriver
(Torsion of
screw:
4.5±0.5Kg)
5
1. Insert CTRL BD FFC wire to I/F
BD and paste 1 tape
2. Followin the order to assemble
Rear Cover with Middle Frame

- 13 -
6
1. Lock 4 RC screws Philips-
head
screwdriver
(Torsion of
RC screw:
8~10Kg)
7
To attach the monitor stand:
1. Align and place the stand riser on
the stand base.
2. Open the screw handle at the
bottom of the stand base and
turn it clockwise to secure the
stand assembly.
3. Close the screw handle.
8
1. Slide the tabs on the stand riser
into the slots on the display back
cover and lower the stand
assembly to snap it into place

- 14 -
5. Trouble shooting instructions

- 15 -

- 16 -

- 17 -

- 18 -

- 19 -

- 20 -