Dell S2421HS Service Manual

Dell S2421HS/S2721HS/S2421HSX/
S2721HSX Monitor

User’s Guide

Model: S2421HS/S2721HS/S2421HSX/S2721HSX
Regulatory model: S2421Ht/S2721Ht

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.

Copyright © 2020 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.

2020 – 07

Rev. X05

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 . . . . . . . . . . . . . . . . . . . . . . . . 12

Electrical specifications. . . . . . . . . . . . . . . . . . . . . . . 13

Physical characteristics. . . . . . . . . . . . . . . . . . . . . . . 13

Environmental characteristics . . . . . . . . . . . . . . . . . . . 14

Power management modes . . . . . . . . . . . . . . . . . . . . . 15

Pin assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Plug-and-play . . . . . . . . . . . . . . . . . . . . . . . 19

LCD monitor quality and pixel policy . . . . . . . . . . . 19

Ergonomics. . . . . . . . . . . . . . . . . . . . . . . . . 20

Handling and moving your display. . . . . . . . . . . . . 22

Maintenance guidelines . . . . . . . . . . . . . . . . . . 23

Cleaning your monitor. . . . . . . . . . . . . . . . . . . . . . . . 23

Setting up the monitor.......................24

Connecting the stand . . . . . . . . . . . . . . . . . . . 24

Using the tilt, swivel, and vertical extension . . . . . . . 26

Contents | 3

| 3

Tilt, Swivel and Vertical Extension . . . . . . . . . . . . . . . . . 26

Rotating the Display . . . . . . . . . . . . . . . . . . . . 27

Configuring the display settings on your computer after

rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Connecting your monitor . . . . . . . . . . . . . . . . . 28

Organizing your cables. . . . . . . . . . . . . . . . . . . 29

Securing your monitor using Kensington lock (optional) 29

Removing the monitor stand . . . . . . . . . . . . . . . 30

Wall mounting (Optional) . . . . . . . . . . . . . . . . . 31

Operating the monitor ...................... 32

Power on the monitor . . . . . . . . . . . . . . . . . . . 32

Using the front panel controls . . . . . . . . . . . . . . . 32

Using the OSD lock function . . . . . . . . . . . . . . . 34

Front-panel button. . . . . . . . . . . . . . . . . . . . . 36

Using the On-Screen Display (OSD) menu . . . . . . . . 37

Accessing the menu system . . . . . . . . . . . . . . . . . . . . 37

OSD warning messages . . . . . . . . . . . . . . . . . . . . . . .48

Setting the maximum resolution . . . . . . . . . . . . . . . . . . 50

Troubleshooting ............................51

Self-test . . . . . . . . . . . . . . . . . . . . . . . . . . 51

Built-in diagnostics . . . . . . . . . . . . . . . . . . . . 52

Common problems . . . . . . . . . . . . . . . . . . . . . 53

Product specific problems . . . . . . . . . . . . . . . . . 54

Appendix................................. 56

FCC notices (U.S. only) and other regulatory information 56

Contacting Dell. . . . . . . . . . . . . . . . . . . . . . . 56

Outline dimension ..........................57

4 | Contents

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 on safety instructions, see the Safety, Environmental, and Regulatory

Information (SERI).

Safety instructions | 5

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

S2421HS/S2721HS S2421HSX/S2721HSX

S2421HS/S2721HS S2421HSX/S2721HSX Stand base

Stand riser

Power cable (varies by country)

HDMI cable

6 | About your monitor

• Quick Setup Guide

• Safety,Environmental,and

Regulatory Information

Product features

The Dell S2421HS/S2721HS/S2421HSX/S2721HSX monitor has an active matrix,
Thin Film Transistor (TFT), Liquid Crystal Display (LCD), and LED backlight. The
monitor features include:

• S2421HS/S2421HSX: 60.45 cm (23.8 in.) active area display (Measured
diagonally). 1920 x 1080 (16:9) resolution, plus full-screen support for lower
resolutions.

• S2721HS/S2721HSX: 68.6 cm (27 in.) active area display (Measured diagonally).
1920 x 1080 (16:9) resolution, plus full-screen support for lower resolutions.

• Tilt, swivel, pivot and vertical extension adjustment capabilities.

• 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
set up with an elegant viewing experience.

• Extensive digital connectivity with HDMI & DP 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 FreeSync™ technology. AMD Freesync™ certified range from
48HZ-75HZ.

• Power and OSD buttons lock.

• Security lock slot.

• 0.3 W standby power when in the standby mode.

• Optimize eye comfort with a flicker-free screen.

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 feature is designed to reduce the amount of blue light
emitted from the monitor to optimize eye comfort.

About your monitor | 7

Identifying parts and controls

Front view

S2421HS/S2721HS

1 2

1 2

S2421HSX/S2721HSX

Label Description Use
1 Function buttons For more information, see Operating the Monitor
2 Power on/off button

(with LED indicator)

8 | About your monitor

To turn the monitor on or off.

Back view

1
2

3

1
2

3

5

4

S2421HS/S2721HS

5

4

S2421HSX/S2721HSX

Label Description

1 VESA mounting holes (100 mm

x 100 mm-behind attached

Use

Wall mount monitor using VESA-compatible
wall mount kit (100 mm x 100 mm).

VESA cover)

2 Regulatory label Lists the regulatory approvals.

3 Stand release button Releases stand from monitor.

4 Barcode, 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.

5 Cable management slot Use to organize cables by placing them

through the slot.

About your monitor | 9

Bottom view

1 2 3 4 5

S2421HS/S2721HS

1 2 3 4 5

S2421HSX/S2721HSX

Label Description Use

1 Security lock slot Secures monitor with security cable lock(sold

separately).

2 Power connector Connect the power cable (shipped with your

monitor).

3 DisplayPort Connect your computer with the DisplayPort

cable (optional).

4 HDMI port Connect your computer with the HDMI cable

(shipped with your monitor).

5 Audio line-out port Connect speakers to playback audio through

HDMI or DisplayPort audio channels.
Only two-channel audio is supported.
NOTE: The audio line-out port does not support
headphones.

10 | About your monitor

Monitor specifications

Model S2421HS/S2421HSX S2721HS/S2721HSX

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 (27.0 in.)

Active Area

Horizontal 527.0 4 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 1,000 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)

Color depth 16.7 million colors

Color gamut* NTSC 72%

Connectivity •1 x HDMI 1.4

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

8 ms (normal)

5 ms (fast)

4 ms (extreme)

•1 x DisplayPort 1.2

•1 x Audio line-out port (3.5 mm jack)

About your monitor | 11

Height adjustable stand 100 mm 110mm

Tilt -5° to 21°

Swivel -30° to 30°

Pivot -90° to 90°

Cable management Yes

Dell Display Manager
(DDM)Compatibility

Security Security-lock slot (cable lock sold separately)

*At panel native resolution only, under Custom Mode preset.

Resolution specifications

Model S2421HS/S2421HSX/S2721HS/S2721HSX

Horizontal scan range 83 kHz to 83 kHz 30 kHz to 83 kHz

Vertical scan range 48 Hz to 75 Hz

Maximum preset resolution 1920 x 1080 at 60 Hz

Video display capabilities
(HDMI & DP alternate
mode)

Preset display modes

Easy Arrange and other key features

DisplayPort HDMI

480i, 480p, 576i, 576p, 720p, 1080i, 1080p

Display Mode Horizontal

Frequency
(kHz)

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 6 7.5 75.0 108.0 +/+

VESA, 1280 x 1024 64.0 60.0 108.0 +/+

VESA, 1280 x 1024 80.0 75.0 135.0 +/+

12 | About your monitor

Vertical
Frequency
(Hz)

Pixel Clock
(MHz)

Sync
Polarity
(Horizontal/
Vertical)

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 + /-

Electrical specifications

Model S2421HS/S2421HSX/S2721HS/S2721HSX

Video input signals •Digital video signal for each dierential line

Per dierential line at 100 ohm impedance

•DP/HDMI signal input support

Input voltage/frequency/
current

Inrush current 120 V: 30 A (maximum)

Physical characteristics

Model S2421HS/S2421HSX S2721HS/S2721HSX

Connector type •1 x HDMI1.4 port

Signal cable type

Dimensions (with stand)

Height (extended)

Height (compressed)

Width

Depth

Dimensions (without stand)

Height

Width

Depth

Stand dimensions

Height (extended)

Height (compressed)

Width

100-240 VAC / 50 or 60 Hz ± 3 Hz / 1.5 A
(maximum)

240 V: 60 A (maximum)

•1 x DisplayPort 1.2

•1 x Audio line-out port

1.8 m HDMI1.4 cable

446.8 mm (17.59 in.) 509.0 mm (20.04 in.)

346.8 mm (13.65 in.) 399.0 mm (15.71 in.)

537.8 mm (21.17 in.) 609.9 mm (24.01 in.)

159.7 mm (6.29 in.) 174.7 mm (6.88 in.)

322.6 mm (12.70 in.) 363.6 mm (14.32 in.)

537.8 mm (21.17 in.) 609.9 mm (24.01 in.)

53.8 mm (2.12 in.) 54.0 mm (2.13 in.)

361.5 mm (14.23 in.) 403.1 mm (15.87 in.)

325.4 mm (12.81 in.) 364.8 mm (14.36 in.)

237.0 mm (9.33 in.) 257.0 mm (10.12 in.)

About your monitor | 13

Depth

Weight

Weight with packaging 7.0 kg (15.43 lb) 8.9 kg (19.62 lb)

Weight with stand assembly
and cables

Weight without stand
assembly (For wall mount or
VESA mount considerations ­no cables)

Weight of stand assembly 1.3 kg (2.87 lb) 1.5 kg (3.31 lb)

Environmental characteristics

Compliant standards

•ENERGY STAR certified Monitor

•TCO Certified Display

•RoHS Compliant

•BFR/PVC Reduce monitor (excluding external cables)

•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

S2421HS/S2421HSX 78.48 BTU/hour (maximum)

S2721HS/S2721HSX 105.78 BTU/hour (maximum)

Power management modes

159.7 mm (6.29 in.) 174.7 mm (6.88 in.)

4.8 kg (10.58 lb) 6.0 kg (13.23 lb)

3.2 kg (7.05 lb) 4.3 kg (9.48 lb)

61.42 BTU/hour (typical)

68.24 BTU/hour (typical)

If you have VESA’s DPM-compliant video card or software installed in your PC, the
monitor can automatically reduce its power consumption when not in use. This is
referred to as standby mode1. If the computer detects input from the keyboard, mouse,

14 | About your monitor

or other input devices, the monitor automatically resumes functioning. The following
table shows the power consumption and signaling of this automatic power saving
feature.

S2421HS/S2421HSX

VESA
modes

Normal
operation

Active-off
mode

Horizontal
sync

Vertical
sync

Video Power indicator Power

consumption

Active Active Active White 23 W (maximum)**

18 W (typical)

Inactive Inactive Off White

Less than 0.3 W

(Glowing)

Switch off - - - Off Less than 0.3 W

Power Consumption P

ON

11.04 W

Total Energy Consumption(TEC) 35.04 kWh

S2721HS/S2721HSX

VESA
modes

Normal
operation

Active-off
mode

Horizontal
sync

Vertical
sync

Video Power indicator Power

consumption

Active Active Active White 31 W (maximum)**

20 W (typical)

Inactive Inactive Off White

Less than 0.3 W

(Glowing)

Switch off - - - Off Less than 0.3 W

Power Consumption P

ON

12.59 W

Total Energy Consumption(TEC) 40.14 kWh

About your monitor | 15

The OSD operates only in the normal operation mode. If you press any button in the
active-off mode, one of the following message is displayed.

S2421HS/S2421HSX

Dell 24 Monitor

No DP signal from your device.

Press any key on the keyboard or move the mouse to wake it up.

If there is no display, press the monitor button again to select

the correct input source.

S2421HS/S2421HSX

S2721HS/S2721HSX

Dell 27 Monitor

No DP signal from your device.

Press any key on the keyboard or move the mouse to wake it up.

If there is no display, press the monitor button again to select

the correct input source.

S2721HS/S2721HSX

*Zero power consumption in OFF mode can only be achieved by disconnecting

the AC mains cable from the monitor.

**Maximum power consumption with maximum luminance

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.

Activate the computer and the monitor to gain access to the OSD.

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

16 | About your monitor

settings or enabling other features may increase power consumption that could exceed
the ENERGY STAR specified limit.

NOTE:

Pon: 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.

Pin assignments

DisplayPort

Pin
number

1 ML3 (n) 11 GND

2 GND 12 ML0 (p)

3 ML3 (p) 13 CONFIG1

4 ML2 (n) 14 CONFIG2

5 GND 15 AUX CH (p)

6 ML2 (p) 16 GND

7 ML1 (n) 17 AUX CH (n)

8 GND 18 Hot Plug Detect

9 ML1 (p) 19 Return

10 ML0 (n) 20 DP_PWR

20-pin side of
theconnected signal cable

Pin
number

20-pin side of
theconnected signal cable

About your monitor | 17

HDMI port

Pin number 19-pin side of theconnected signal cable

1 TMDS DATA 2+

2 TMDS DATA 2 SHIELD

3 TMDS DATA 2-

4 TMDS DATA 1+

5 TMDS DATA 1 SHIELD

6 TMDS DATA 1-

7 TMDS DATA 0+

8 TMDS DATA 0 SHIELD

9 TMDS 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

18 | About your monitor