Dell S2421Ho User manual

Monitor Model: S2421HN/S2721HN/S2421NX/S2721NX
Regulatory Model: S2421Ht/S2721Ht/S2421Ho/S2721Ho
Dell S2421HN/S2721HN/S2421NX/
S2721NX Monitor
User’s Guide

NOTE: A NOTE indicates important information that helps you make
better use of your monitor.
CAUTION: A CAUTION indicates potential damage to hardware or loss of
data if instructions are not followed.
WARNING: A WARNING indicates a potential for property damage,
personal injury, or death.
NOTE: Dell Monitor with ComfortView or ComfortView Plus feature are
tested and complied to TUV Low Blue Light emission standard.
ComfortView featured product reduces panel blue light with software
solution and ComfortView Plus is with hardware solution.
This monitor may adopt either software or hardware solution depending
on the type of panel used during manufacturing.
For differentiation purpose, TUV logo can be found on the carton box and
safety label for ComfortView Plus monitor. There is no printing of logo for
ComfortView monitor.
1111244653 1111244655
Copyright © 2022-2023 Dell Inc. or its subsidiaries. All rights reserved. Dell, EMC, and other
trademarks are trademarks of Dell Inc. or its subsidiaries. Other trademarks may be trademarks of their
respective owners.
2023 – 08
Rev. A03

| 3
Contents
Safety instructions.......................... 5
About your monitor ......................... 6
Package contents . . . . . . . . . . . . . . . . . . . . . . 6
Product features . . . . . . . . . . . . . . . . . . . . . . .7
Identifying parts and controls . . . . . . . . . . . . . . . .8
Front view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Back view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Bottom view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Monitor specifications . . . . . . . . . . . . . . . . . . . 11
Resolution specifications . . . . . . . . . . . . . . . . . . . . . . 12
Preset display modes . . . . . . . . . . . . . . . . . . . . . . . . 13
Electrical specifications. . . . . . . . . . . . . . . . . . . . . . . 14
Physical characteristics. . . . . . . . . . . . . . . . . . . . . . . 15
Environmental characteristics . . . . . . . . . . . . . . . . . . . 16
Pin assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Plug-and-play . . . . . . . . . . . . . . . . . . . . . . . 17
LCD monitor quality and pixel policy . . . . . . . . . . . 18
Ergonomics. . . . . . . . . . . . . . . . . . . . . . . . . 18
Handling and moving your display . . . . . . . . . . . . . 20
Maintenance guidelines . . . . . . . . . . . . . . . . . . 21
Cleaning your monitor. . . . . . . . . . . . . . . . . . . . . . . . 21
Contents | 3

4| Contents
Setting up the monitor ...................... 22
Connecting the stand . . . . . . . . . . . . . . . . . . . 22
Using the tilt . . . . . . . . . . . . . . . . . . . . . . . . 25
Connecting your monitor . . . . . . . . . . . . . . . . . 26
Organizing your cables . . . . . . . . . . . . . . . . . . 27
Securing your monitor using Kensington lock (optional) . 27
Removing the monitor stand . . . . . . . . . . . . . . . 28
Wall mounting (optional) . . . . . . . . . . . . . . . . . 29
Operating the monitor ...................... 30
Power on the monitor . . . . . . . . . . . . . . . . . . . 30
Using the front panel controls . . . . . . . . . . . . . . . 30
Using the OSD lock function . . . . . . . . . . . . . . . 32
Front-panel button . . . . . . . . . . . . . . . . . . . . . 34
Using the On-Screen Display (OSD) menu . . . . . . . . 35
Accessing the menu system . . . . . . . . . . . . . . . . . . . . 35
OSD warning messages . . . . . . . . . . . . . . . . . . . . . . . 46
Setting the maximum resolution . . . . . . . . . . . . . . . . . . 49
Troubleshooting ........................... 50
Self-test . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Built-in diagnostics . . . . . . . . . . . . . . . . . . . . 51
Common problems . . . . . . . . . . . . . . . . . . . . . 52
Product specific problems. . . . . . . . . . . . . . . . . 54
Appendix................................. 55
FCC notices (U.S. only) and other regulatory information 55
Contacting Dell. . . . . . . . . . . . . . . . . . . . . . . 55
EU product database for energy label and product
information sheet . . . . . . . . . . . . . . . . . . . . . 55

Safety instructions | 5
Safety instructions
CAUTION: Use of controls, adjustments, or procedures other than those
specified in this documentation may result in exposure to shock, electrical
hazards, and/or mechanical hazards.
• Place the monitor on a solid surface and handle it carefully. The screen is fragile
and can be damaged if dropped or hit sharply.
• Always be sure that your monitor is electrically rated to operate with the AC
power available in your location.
• Keep the monitor in room temperature. Excessive cold or hot conditions can have
an adverse effect on the liquid crystal of the display.
• Do not subject the monitor to severe vibration or high impact conditions. For
example, do not place the monitor inside a car trunk.
• Unplug the monitor when it is going to be left unused for an extended period of
time.
• To avoid electric shock, do not attempt to remove any cover or touch the inside
of the monitor.
For information about safety instructions, see the Safety, Environmental, and
Regulatory Information (SERI).

6| About your monitor
About your monitor
Package contents
Your monitor ships with the components shown below. Ensure that you have received
all the components and see Contacting Dell if anything is missing.
NOTE: Some components may be optional and may not ship with your
monitor. Somefeatures may not be available in certain countries.
Display
S2421/S2721 HN S2421/S2721 NX Stand riser
S2421/S2721 HN S2421/S2721 NX Stand base
S2421/S2721 HN S2421/S2721 NX VESA cover
Power cable (varies by country)

About your monitor | 7
HDMI cable
Dell S2421HN(NX)/S2721HN(NX)
HDMI2HDMI1
HDMIHDMI
1
2
3
4
HDMI
HDMIMI
HDMI
H
DMI
3
2
1
746.A3E01.0001
(DELL P/N: PNF73 rev.X01)
© 2020 Dell Inc. or its subsidiaries.
2020-07
i
www.dell.com/contactdell
6
5° 21°
i
Dell.com/S2421HN/NX
Dell.com/S2721HN/NX
5
3
12
12
12
4
HDMI
Dell S2421H/S2721H
HDMI2HDMI1
HDMIHDMI
1
2
3
4
HDMI
HDMIMI
HDMI
HDMI
3
2
1
746.A3E01.0001
(DELL P/N: PNF73 rev.X01)
© 2020 Dell Inc. or its subsidiaries.
2020-07
i
www.dell.com/contactdell
6
5°21°
i
Dell.com/S2421H
Dell.com/S2721H
5
3
12
12
12
4
HDMI
• Quick Start Guide
• Safety, Environmental, and
Regulatory Information

8| About your monitor
Product features
The Dell S2421HN/S2421NX/S2721HN/S2721NX monitor has an active matrix,
Thin Film Transistor (TFT), Liquid Crystal Display (LCD), and LED backlight. The
monitor features include:
• S2421HN/S2421NX: 60.45 cm (23.80 in.) active area display (measured
diagonally) 1920 x 1080 (16:9) resolution, plus full-screen support for lower
resolutions.
• S2721HN/S2721NX: 68.6 cm (27 in.) active area display (measured diagonally)
1920 x 1080 (16:9) resolution, plus full-screen support for lower resolutions.
• Tilt adjustment capability.
• Removable pedestal and Video Electronics Standards Association (VESA™) 100
mm mounting holes for flexible mounting solutions.
• Ultra-thin bezel minimizes the bezel gap in multi-monitor usage, enabling easier
setup with an elegant viewing experience.
• Extensive digital connectivity with HDMI helps future-proof your monitor.
• Plug and play capability if supported by your computer.
• On-Screen Display (OSD) adjustments for ease of set-up and screen
optimization.
• Supports AMD FreeSyncTM technology. AMD Freesync™ certified range from 48
Hz - 75 Hz.
• Power and OSD buttons lock.
• Security lock slot.
• ≤ 0.3 W in Standby Mode.
• The Monitor adopts Flicker-Free technology, which clears the eye visible flicker,
brings comfort viewing experience and preventing users suffer from eye strain
and fatigue.
WARNING: The possible long-term effects of blue light emission from the
monitor may cause damage to the eyes, including eye fatigue or digital
eye strain. ComfortView and ComfortView Plus feature are designed to
reduce the amount of blue light emitted from the monitor to optimize eye
comfort. The ComfortView mode is optional in the OSD. Only when this
mode is not exist in the OSD, the factory default setting is qualified for
the Low Blue Light approval.
NOTE: ComfortView is a feature to reduce blue light emission with preset
color co-ordinates. This can be enabled with the OSD menu. ComfortView
Plus is a feature to reduce blue light emission with panel Backlight design.
No further setting by the user is required.

About your monitor | 9
Identifying parts and controls
Front view
1 2
S2421HN/S2721HN
1 2
S2421NX/S2721NX
Label Description Use
1Function buttons For more information, see Operating the
monitor.
2Power on/off button
(with LED indicator)
To turn the monitor on or off.

10 | About your monitor
Back view
5
3
4
2
1
DELL S2421HN
Flat Panel Monitor / 液晶显示器
型号: S2421HN
Input Rating / 输入电源:
100-240V ~ 50/60Hz 1.5A
Made in China / 制造地:中国
Manufactured date / 制造日期:
E
t
DELL S2421HN
Flat Panel Monitor / Monitor Plano Panel / Moniteur à écran plat / 液晶顯示器
Model No. / N° de Modelo / Num éro de modèl e /型號: S2421Ht
Input Rating / Entrada / Daya Tegangan / Tension d’entrée: 100-240V ~ 50/60Hz 1.5A
輸入電源:交流電壓 100-240伏特,1.5安培,5 0/60赫茲
Удельная мощность рабочего режима -X,XXX Вт/см2
Потребляемая мощность изделием в режиме ожидания -X,XX Вт
Потребляемая мощность изделием в выключенном режиме - X,XX Вт
Made in China / Fabricado en China / Fabriqué en Chine / Сделано в Китае / 製造地:中國
警語:使用過度恐傷害視力
신청인: Wistron Corporation (For Korea)
Wistron InfoComm (Zhongshan) Corporation Linhai Branch
제조자: Wistron InfoComm (Zhongshan) Corporation Linhai Branch
A/S 연락처:080-854-0066
제조국:중국
CAN ICES-3 (B)/NMB-3(B)
Apparatet må tilkoples jordet stikkontakt.
Apparaten skall anslutas till jordat uttag.
Apparatets stikprop skal tilsluttes en stikkontakt med jord,
som giver forbindelse til stikproppens jord.
Laite on liitettävä suojakoskettimilla varustettuun pistorasiaan.
Consumo de energía en operación: XX.XX Wh
XXXXX
AddressforEUOnly:
RaheenBusinessPark
LimerickIreland
www.dell.com/regulatory_compliance
XXXXXXXX-XXXXX
R-R-WT1-S2421Ht
И005-20
This device complies with part 15 of the FCC Rules.
Operation is subject to the following two conditions:
(1) this device may not cause harmful interference, and
(2) this device must accept any interference received,
including interference that may cause undesired operation.
XXXXXX-XX
IS13252 (Part 1)/
IEC60950-1
R-41071650
www.bis.gov.in
For UK only: Cain Road, Bracknell, RG12 1LF
IDXXXXXXXXXX
ID
XXXXXXXXXX
DELL S2421HN
Flat Panel Monitor / 液晶显示器
型号: S2421HN
Input Rating / 输入电源:
100-240V ~ 50/60Hz 1.5A
Made in China / 制造地:中国
Manufactured date / 制造日期:
E
t
S2421HN/S2721HN
3
4
2
1
5
S2421NX/S2721NX
Label Description Use
1VESA mounting holes (100 mm x
100 mm-behind attached VESA
cover)
Wall mount monitor using VESA-
compatible wall mount kit (100 mm x 100
mm).
2Regulatory label Lists the regulatory approvals.
3Stand release button Release stand from monitor.
4Barcode, serial number, and
Service Tag label
Refer to this label if you need to contact
Dell for technical support. The Service Tag
is a unique alphanumeric identifier that
enables Dell service technicians to identify
the hardware components in your display
and access warranty information.
5Cable management slot Use to organize cables by placing them
through the slot.

About your monitor | 11
Bottom view
21 3 4 5
S2421HN/S2721HN
21 3 4 5
S2421NX/S2721NX
Label Description Use
1Security lock slot Secures monitor with security cable lock (sold
separately).
2Power connector Connect the power cable (shipped with your monitor).
3HDMI port 1 Connect your computer with HDMI cable.
4HDMI port 2 Connect your computer with HDMI cable.
5Audio Line-out port Connect speakers to playback audio coming through
HDMI audio channel.
Only two-channel audio is supported.
NOTE: The audio line-out port does not support
headphones.

12 | About your monitor
Monitor specifications
Model S2421HN/S2421NX S2721HN/S2721NX
Screen type Active matrix - TFT LCD
Panel type In-plane switching technology
Aspect ratio 16:9
Viewable image dimensions:
Diagonal 60.45 cm (23.8 in.) 68.6 cm (27 in.)
Active Area:
Horizontal 527.04 mm (20.75 in.) 597.89 mm (23.54 in.)
Vertical 296.46 mm (11.67 in.) 336.31 mm (13.24 in.)
Area 156246.28 mm2(242.15 in.2) 201073.02 mm2(311.67 in.2)
Pixel pitch 0.2745 mm x 0.2745 mm 0.3114 mm x 0.3114 mm
Pixel per inch (PPI) 92.56 81.59
Viewing angle:
Horizontal 178° (typical)
Vertical 178° (typical)
Brightness 250 cd/m² (typical) 300 cd/m² (typical)
Contrast ratio 1000 to 1 (typical)
Display screen coating Anti-glare treatment of the front polarizer (3H) hard coating
Backlight LED edgelight system
Response Time
(Gray to Gray)
8 ms (normal)
5 ms (fast)
4 ms (extreme)
Color depth 16.7 million colors
Color gamut* sRGB 99.9%
Connectivity • 2 x HDMI 1.4
• 1 x Audio line-out(3.5 mm jack)
Border width (edge of monitor to active area)
Top/Left/Right 5.4 mm 6.0 mm
Bottom 20.7 mm 21.3 mm
Adjustability
Height adjustable
stand
NA
Tilt -5° to 21°

About your monitor | 13
Swivel NA
Pivot NA
Cable management Yes
Dell Display Manager
(DDM)Compatibility
Easy Arrange and other key features
Security Security lock slot (cable lock sold separately)
*At panel native resolution only, under Custom Mode preset.
Resolution specifications
Model S2421HN/S2421NX/S2721HN/S2721NX
Horizontal scan range 30 kHz to 83 kHz
Vertical scan range 48 Hz to 75 Hz
Maximum preset
resolution
1920 x 1080 at 75 Hz
Video display capabilities
(HDMI playback)
480i, 480p, 576i, 576p, 720p, 1080i, 1080p

14 | About your monitor
Preset display modes
S2421HN/S2421NX/S2721HN/S2721NX
Display mode Horizontal
frequency
(kHz)
Vertical
frequency
(Hz)
Pixel clock
(MHz)
Sync polarity
(Horizontal/
Vertical)
VGA, 720 x 400 31.5 70.0 28.3 -/+
VGA, 640 x 480
31.5
60.0
25.2
-/-
VESA, 640 x 480 37.5 75.0 31.5 -/-
VESA, 800 x 600 37.9 60.0 40.0 +/+
VESA, 800 x 600 46.9 75.0 49.5 +/+
VESA, 1024 x 768 48.4 60.0 65.0 -/-
VESA, 1024 x 768 60.0 75.0 78.8 +/+
MAC, 1152 x 864
67.5
75.0
108.0
+/+
VESA, 1280 x 1024 64.0 60.0 108.0 +/+
VESA, 1280 x 1024 80.0 75.0 135.0 +/+
VESA, 1600 x 900 60.0 60.0 108.0 +/+
CVT, 1920 x 1080
67.5
60.0
148.5
+/+
CVT, 1920 x 1080 83.89 75.0 174.5 +/-

About your monitor | 15
Electrical specifications
Model S2421HN/S2421NX/S2721HN/S2721NX
Video input signals • Digital video signal for each dierential line
Per dierential line at 100 ohm impedance
• HDMI signal input support
Input voltage/ frequency/
current
100-240 VAC/50 or 60 Hz ± 3 Hz/1.5 A
(maximum)
Inrush current 120 V: 30 A (maximum)
240 V: 60 A (maximum)
Power consumption
S2421HN/S2421NX S2721HN/S2721NX
0.2 W (Off Mode)1
0.2 W (Standby Mode)1
12.2 W (On Mode)1
21 W (Max)2
11.74 W (Pon)3
37.3 kWh (TEC)3
0.2 W (Off Mode)1
0.2 W (Standby Mode)1
15.5 W (On Mode)1
29 W (Max)2
13.82 W (Pon)3
43.68 kWh (TEC)3
1As defined in EU 2019/2021 and EU 2019/2013.
2Max brightness and contrast setting.
3Pon: Power consumption of On Mode as defined in Energy Star 8.0 version.
TEC: Total energy consumption in kWh as defined in Energy Star 8.0 version.
This document is informational only and reflects laboratory performance. Your product
may perform differently, depending on the software, components and peripherals
you ordered and shall have no obligation to update such information. Accordingly, the
customer should not rely upon this information in making decisions about electrical
tolerances or otherwise. No warranty as to accuracy or completeness is expressed or
implied.
NOTE: This monitor is ENERGY STAR certified.
This product qualifies for ENERGY STAR in the factory default settings, which can be
restored by “Factory Reset” function in the OSD menu. Changing the factory default
settings or enabling other features may increase power consumption that could exceed
the ENERGY STAR specified limit.

16 | About your monitor
Physical characteristics
Model S2421HN/S2421NX S2721HN/S2721NX
Connector type • 2 x HDMI1.4 ports
• 1 x Audio line-out port
Signal cable type 1.8 m HDMI1.4 cable
Dimensions (with stand):
Height 412.8 mm (16.25 in.) 453.3 mm (17.85 in.)
Width 537.8 mm (21.17 in.) 609.9 mm (24.01 in.)
Depth 152.8 mm (6.02 in.) 186.8 mm (7.35 in.)
Dimensions (without stand):
Height 322.6 mm (12.70 in.) 363.6 mm (14.32 in.)
Width 537.8 mm (21.17 in.) 609.9 mm (24.01 in.)
Depth 53.8 mm (2.12 in.) 54.0 mm (2.13 in.)
Stand dimensions:
Height 171.6 mm (6.76 in.) 176.0 mm (6.93 in.)
Width 249.0 mm (9.80 in.) 257.2 mm (10.13 in.)
Depth 152.8 mm (6.02 in.) 186.8 mm (7.35 in.)
Weight:
Weight with packaging 5.9 kg (13 lb.) 7.4kg (16.31 lb.)
Weight with stand assembly and
cables
4.1 kg (9.04 lb.) 5.2 kg (11.46 lb)
Weight without stand assembly
(For wall mount or VESA mount
considerations - no cables)
3.3 kg (7.28 lb.) 4.3 kg (9.48 lb.)
Weight of stand assembly 0.5 kg (1.19 lb.) 0.7 kg (1.54 lb.)

About your monitor | 17
Environmental characteristics
Model S2421HN/S2421NX/S2721HN/S2721NX
Compliant standards
• ENERGY STAR certified Monitor
• TCO Certified
• RoHS Compliant
• BFR/PVC Reduce monitor (The circuit boards are made from BFR/PVC-free
laminates).
• Arsenic-Free glass and Mercury-Free for the panel only
Temperature:
Operating 0°C to 40°C (32°F to 104°F)
Non-operating –20°C to 60°C (–4°F to 140°F)
Humidity:
Operating 10% to 80% (non-condensing)
Non-operating 5% to 90% (non-condensing)
Altitude:
Operating (maximum) 5,000 m (16,404 ft.)
Non-operating (maximum) 12,192 m (40,000 ft.)
Thermal dissipation
S2421HN/S2421NX 71.65 BTU/hour (maximum)
41.63 BTU/hour (On Mode)
S2721HN/S2721NX 98.95 BTU/hour (maximum)
52.89 BTU/hour (On Mode)

18 | About your monitor
Pin assignments
HDMI port
Pin number 19-pin side of theconnected signal cable
1TMDS DATA 2+
2TMDS DATA 2 SHIELD
3TMDS DATA 2-
4TMDS DATA 1+
5TMDS DATA 1 SHIELD
6TMDS DATA 1-
7TMDS DATA 0+
8TMDS DATA 0 SHIELD
9TMDS DATA 0-
10 TMDS CLOCK+
11 TMDS CLOCK SHIELD
12 TMDS CLOCK-
13 CEC
14 Reserved (N.C. on device)
15 DDC CLOCK (SCL)
16 DDC DATA (SDA)
17 DDC/CEC Ground
18 +5 V POWER
19 HOT PLUG DETECT
Plug-and-play
You can install the monitor in any Plug-and-Play-compatible system. The monitor
automatically provides the computer with its extended display identification data
(EDID) using display data channel (DDC) protocols so the computer can configure
itself and optimize the monitor settings. Most monitor installations are automatic; you

About your monitor | 19
can select different settings , if required. For more information about changing the
monitor settings, see Operating the monitor.
LCD monitor quality and pixel policy
During the LCD monitor manufacturing process, it is not uncommon for one or more
pixels to become fixed in an unchanging state, which are hard to see and do not affect
the display quality or usability. For more information about LCD Monitor Pixel Policy,
see Dell support site at: https://www.dell.com/pixelguidelines.
Ergonomics
CAUTION: Improper or prolonged usage of keyboard may result in injury.
CAUTION: Viewing the monitor screen for extended periods of time may
result in eye strain.
For comfort and efficiency, observe the following guidelines when setting up and using
your computer workstation:
• Position your computer so that the monitor and keyboard are directly in front of
you as you work. Special shelves are commercially available to help you correctly
position your keyboard.
• To reduce the risk of eye strain and neck/arm/back/shoulder pain from using the
monitor for long periods of time, we suggest you to:
1. Set the distance of the screen between 20 to 28 in. (50-70 cm) from your
eyes.
2. Blink frequently to moisten your eyes or wet your eyes with water after
prolonged usage of the monitor.
3. Take regular and frequent breaks for 20 minutes every two hours.
4. Look away from your monitor and gaze at a distant object at 20 feet away for
at least 20 seconds during the breaks.
5. Perform stretches to relieve tension in the neck, arm, back, and shoulders
during the breaks.
• Ensure that the monitor screen is at eye level or slightly lower when you are
sitting in front of the monitor.
• Adjust the tilt of the monitor, its contrast, and brightness settings.
• Adjust the ambient lighting around you (such as overhead lights, desk lamps, and
the curtains or blinds on nearby windows) to minimize reflections and glare on the
monitor screen.
• Use a chair that provides good lower-back support.

20 | About your monitor
• Keep your forearms horizontal with your wrists in a neutral, comfortable position
while using the keyboard or mouse.
• Always leave space to rest your hands while using the keyboard or mouse.
• Let your upper arms rest naturally on both sides.
• Ensure that your feet are resting flat on the floor.
• When sitting, ensure that the weight of your legs is on your feet and not on the
front portion of your seat. Adjust your chair’s height or use a footrest if necessary
to maintain a proper posture.
• Vary your work activities. Try to organize your work so that you do not have to sit
and work for extended periods of time. Try to stand or get up and walk around at
regular intervals.
• Keep the area under your desk clear of obstructions and cables or power cords
that may interfere with comfortable seating or present a potential trip hazard.
monitor screen at or
below eye level
monitor and
keyboard
positioned
directly in front
of the user
feet at on the
oor
wrists relaxed
and at