Dell U2421HE User Manual

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Dell UltraSharp 24/27

USB-C Hub Monitor - U2421HE/U2721DE

User’s Guide

Model: U2421HE/U2721DE Regulatory model: U2421HEt/U2721DEt

NOTE: A NOTE indicates important information that helps you make better use of your computer.

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.

are trademarks of Dell Inc. or its subsidiaries. Other trademarks may be trademarks of their respective owners.

2020 – 03

Rev. A00

Contents

About Your Monitor .................................5

Package Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Product Features

Identifying Parts and Controls

Monitor Specifications

Plug-and-Play

LCD Monitor Quality and Pixel Policy

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

. . . . . . . . . . . . . . . . . . . . . . . . 7

. . . . . . . . . . . . . . . . . . . . . . . . . . . .10

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24

. . . . . . . . . . . . . . . . . . . .24

Setting Up the Monitor .............................25

Attaching the Stand . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Using the Tilt, Swivel, and Vertical Extension

Adjusting the Rotation Display Settings of Your System

Connecting Your Monitor

Organizing Your Cables

Removing the Monitor Stand

Wall Mounting (Optional)

. . . . . . . . . . . . . . . . . . . . . . . . . . .29

. . . . . . . . . . . . . . . . . . . . . . . . . . .32

. . . . . . . . . . . . . . . . . . . . . . . .32

. . . . . . . . . . . . . . . . . . . . . . . . . .33

. . . . . . . . . . . . . . . .27

. . . . . . . . . .28

Operating the Monitor ..............................34

Turning on the Monitor. . . . . . . . . . . . . . . . . . . . . . . . . . . .34

Using the Front Panel Controls

Using the OSD Lock function

Using the On-Screen Display (OSD) Menu

. . . . . . . . . . . . . . . . . . . . . . .34

. . . . . . . . . . . . . . . . . . . . . . . .36

. . . . . . . . . . . . . . . . .39

Contents | 3

Troubleshooting ...................................54

Self-Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54

Built-in Diagnostics

Common Problems

Product Specific Problems

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56

. . . . . . . . . . . . . . . . . . . . . . . . . .57

Appendix.........................................59

Safety Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

FCC Notices (U.S. only) and Other Regulatory Information

Contacting Dell

Setting Up Your Monitor

Maintenance Guidelines

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

. . . . . . . . . . . . . . . . . . . . . . . . . . .60

. . . . . . . . . . . . . . . . . . . . . . . . . . .62

. . . . . . . .59

4 | Contents

About Your Monitor

Package Contents

Your monitor ships with the components shown below. Make sure that you have received all the components and contact Dell if something is missing.

NOTE: Some items may be optional and may not ship with your monitor.

Somefeatures or media may not be available in certain countries.

Display

Stand riser

Stand base

Power cable (varies by country)

USB Type-C cable (C to C)

About Your Monitor | 5

DP cable

U2421HE Color Calibration Factory Report

Every Dell U2421HE is shipped incorporating pre-tuned

Serial No.

CN00WG2J7444572B046L standard mode(sRGB) with average Delta-E ≤2. This helps prevent significant color inconsistency or

Tester

2008L0415 inaccuracy when content is displayed onscreen. In addition, a tighter grey-scale tracking on each U2421HE helps enable ultra-smooth color gradation. The factory measurements from this very unit are shown here.

Test

CA-210/CA-310

CA-2000S

Equipment

Be assured of Accurate, Precise and Consistent

Chroma 2326/2235/2233

Onscreen Color with eve

ltraSharp U2421HE.

ry Dell U

Standard mode (sRGB) Avg. Delta E ≤ 2

Gray-Scale Tracking

Gamma

Note: Calibrations were done according to Dell approved test procedures using calibrated equipment at the factory production line. This Report is provided only with and for this new Dell U2421HE UltraSharp monitor. Results may vary with other test equipment, setups and test patterns. Please retain this Report for your reference as Dell is unable to reproduce it or provid e a duplic ate.

•Quick Setup Guide

•Safety,Environmental,and

Regulatory Information

•Factory Calibration Report

Product Features

The Dell UltraSharp U2421HE/U2721DE monitor has an active matrix, thinfilm transistor (TFT), liquid crystal display (LCD), and LED backlight. The monitor features include:

• U2421HE: 60.47 cm (23.8 in.) active area display (Measured diagonally) 1920 x 1080 (16:9) resolution, plus full-screen support for lower resolutions.

• U2721DE: 68.47 cm (27 in.) active area display (Measured diagonally) 2560 x 1440 (16:9) resolution, plus full-screen support for lower resolutions.

• Wide viewing angles with 99% sRGB color with an average Delta E<2.

• 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 DP helps future-proof your monitor.

• Single USB Type-C to supply power to compatible notebook while receiving video

signal.

• USB-C and RJ45 ports enable a single-cable, network-connected experience.

• Plug and play capability if supported by your system.

• On-Screen Display (OSD) adjustments for ease of set-up and screen optimization.

• Power and OSD buttons lock.

• Security lock slot.

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

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

NOTE: 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.

6 | About Your Monitor

Identifying Parts and Controls

Front view

1 2

Label Description 1 Function buttons (For more information, see Operating the Monitor) 2 Power on/off button (with LED indicator)

About Your Monitor | 7

Back View

3 4

DELL U2421HE

Flat Panel Monitor / Monitor Plano Panel / Moniteur à écra n plat / 液晶顯示器 Model No. / N° de Modelo / Numéro de modèle /型號:

U2421HEt

Input Rating / Entrada / Daya Tegangan / Tension d’entrée: 100-240V ~ 50/60Hz 1 .6 A 輸入電源:交流電壓 100-240伏特, 1.5 安培, 50/60赫茲

Made in China / Fabricado en China / Fabriqués en Chine / Сделано в Китае / 製造地:中國

Consumo de energía en operación XX.X Wh

Удельная мощность рабочего режима - X,XXX Вт/см Потребляемая мощность изделием в режиме ожидания -X,XX Вт Потребляемая мощность изделием в выключенном режиме - X,XX Вт

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.

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

XXXXXXXX-XXXXX

R-REM-WT1-U2421HEt

警語:使用過度恐傷害視力

CAN ICES-3 (B)/NMB-3(B)

This equipment complies with part 15 of the FCC Rules.

И005-18

Operation is subject to the following two conditions: (1) This equipment may not cause harmful interference, and (2) this equipment must accept any interference received, including interference that may cause undesired operation.

XXXXXX-XX

ID XXXXXXXXXX

U2421HE

January 2020

Address for EU Only: Raheen Business Park Limerick Ireland

www.dell.com/regulatory_compliance

XXXXX

U2421HE

Label Description Use

1 VESA mounting holes (100 mm x 100

mm-behind attached VESA cover)

Wall mount monitor using VESAcompatible wall mount kit (100 mm x 100 mm).

2 Regulatory label Lists the regulatory approvals.

3 Stand release button Release stand from monitor.

4 Security lock slot Secures monitor with security cable lock

(sold separately).

5 Barcode, serial number, and Service

Tag label

Refer to this label if you need to contact Dell for technical support.

6 Cable management slot Use to organize cables by placing them

through the slot.

Side View

8 | About Your Monitor

USB downstream port

Port with battery icon supports BC 1.2.

Bottom View

1 2 3 4 5 61078 9

Label Description Use

1 AC power port To connect the monitor power cable.

2 HDMI port Connect your computer with HDMI cable (optional).

3 DP port (in) Connect your computer with DP cable.

4 USB Type-C/DisplayPort Connect to your computer using the USB Type-C

5 DP port (out)

6&8 USB downstream ports(2) Connect your USB device. You can use these ports

7 Audio line-out port Connect speakers to playback audio coming through

9 RJ-45 connector Remote Network Management and control of display

10 Stand lock Lock the stand to the monitor using a M3 x 6 mm

cable. The USB 3.1 Type-C port offer the fastest transfer rate and the alternate mode with DP 1.4 support the maximum resolution of 1920 x 1080 at 60 Hz(U2421HE) and 2560 x 1440 at 60 Hz(U2721DE), PD 20 V/3.25 A, 15 V/3 A, 9 V/3 A, 5 V/3 A. NOTE: USB Type-C is not supported on Windows versions that are prior to Windows 10.

DP output for MST (multi-stream transport) capable monitor. To enable MST, refer to instruction on section “Connecting the Monitor for DP MST

Function”.

NOTE: Remove the rubber plug when using DP out connector.

only after you have connected the USB cable (Type-C to Type-C) from the computer to the monitor. Port with

Rev. 1.2.

USB Type-C or DP audio channels. Only supports 2-channel audio. NOTE: The audio line-out port does not support headphones.

via RJ-45.

(U2721DE)/ M3 x 8 mm (U2421HE) screw (screw not included).

battery icon supports Battery Charging

About Your Monitor | 9

Monitor Specifications

Model U2421HE U2721DE

Screen type Active matrix - TFT LCD Active matrix - TFT LCD

Panel Type In-plane switching Technology In-plane switching Technology

Aspect ratio 16:9 16:9

Viewable image dimensions

Diagonal 60.47 cm (23.8 in.) 68.47 cm (27 in.)

Active Area

Horizontal 527.0 4 mm (20.75 in.) 596.74 mm (23.49 in.)

Vertical 296.46 mm (11.67 in.) 335.66 mm (13.21 in.)

Area 156246.3 mm

Pixel pitch 0.2745 mm x 0.2745 mm 0.233 mm x 0.233 mm

Pixel per inch (PPI) 92.5 109

Viewing angle Horizontal 178° (typical) 178° (typical) Vertical 178° (typical) 178° (typical) Brightness 250 cd/m² (typical) 350 cd/m² (typical)

Contrast ratio 1000 to 1 (typical) 1000 to 1 (typical)

Display screen coating Anti-glare treatment of the front

Backlight LED LED

Response Time (Gray to Gray)

Color depth 16.7 million colors 16.7 million colors

Color gamut* 99% sRGB

Calibration accuracy Delta E < 2 (average) Delta E < 2 (average)

polarizer (3H) hard coating

5 ms (FAST mode) 8 ms (NORMAL mode)

99% REC709 85% DCI-P3

(242.15 in.2) 200301.7 mm2 (310.30 in.2)

Anti-glare treatment of the front polarizer (3H) hard coating

5 ms (FAST mode) 8 ms (NORMAL mode)

99% sRGB 99% REC709 85% DCI-P3

10 | About Your Monitor

Connectivity •1 x DP 1.4 (HDCP 1.4)

•1 x HDMI1.4 (HDCP 1.4)

•1 x USB Type-C (Alternate

mode with DisplayPort 1.4, USB 3.1 upstream port, Power Delivery PD up to 65 W)

•1 x DP (Out) with MST (HDCP

1.4)

•2 x USB 3.0 downstream port

•2 x USB 3.0 with BC1.2

charging capability at 2A (max)

•1 x Analog 2.0 audio line out (3.5 mm jack)

•1 x RJ45

Border width (edge of monitor to active area)

Adjustability

Height adjustable stand

Tilt -5° to 21° -5° to 21°

Swivel -40° to 40° -40° to 40°

Cable management Yes Yes

Dell Display Manager (DDM)Compatibility

Security Security lock slot (cable lock

* At panel native only, under Custom Mode preset.

5.0 mm (Top)

5.1 mm (Left/Right)

8.0 mm (Bottom)

130 mm 130 mm

Easy Arrange and other key features

sold separately) Anti-theft stand lock slot (to panel)

•1 x DP 1.4 (HDCP 1.4)

•1 x HDMI1.4 (HDCP 1.4)

•1 x USB Type-C (Alternate

mode with DisplayPort 1.4, USB 3.1 upstream port, Power Delivery PD up to 65 W)

•1 x DP (Out) with MST (HDCP

1.4)

•2 x USB 3.0 downstream port

•2 x USB 3.0 with BC1.2

charging capability at 2A (max)

•1 x Analog 2.0 audio line out (3.5 mm jack)

•1 x RJ45

6.90 mm (Top)

6.90 mm (Left/Right)

8.1 mm (Bottom)

Easy Arrange and other key features

Security lock slot (cable lock sold separately) Anti-theft stand lock slot (to panel)

Resolution Specifications

Model U2421HE U2721DE

Horizontal scan range 30 kHz to 83 kHz 30 kHz to 90 kHz

Vertical scan range 56 Hz to 76 Hz 56 Hz to 76 Hz

Maximum preset resolution 1920 x 1080 at 60 Hz 2560 x 1440 at 60 Hz

Video display capabilities (DP & USB Type-C playback)

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

About Your Monitor | 11

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

Preset Display Modes

(kHz)

(Hz)

Vertical)

(kHz)

(Hz)

Vertical)

U2421HE

Display Mode Horizontal

Frequency

720 x 400 31.5 70.0 28.3 -/+

VESA, 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 60.3 40.0 +/+

VESA, 800 x 600 46.9 75.0 49.5 +/+

VESA, 1024 x 768 4 8.4 60.0 65.0 -/-

VESA, 1024 x 768 60.0 75.0 78.8 +/+

VESA, 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 -/+

VESA, 1920 x 1080 6 7. 5 60.0 148.5 +/+

Vertical Frequency

Pixel Clock (MHz)

U2721DE

Display Mode Horizontal

Frequency

720 x 400 31.5 70.0 28.3 -/+

VESA, 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 60.3 40.0 +/+

VESA, 800 x 600 46.9 75.0 49.5 +/+

VESA, 1024 x 768 4 8.4 60.0 65.0 -/-

VESA, 1024 x 768 60.0 75.0 78.8 + /+

VESA, 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 1200 75.0 60.0 162.0 +/+

VESA, 1920 x 1080 6 7. 5 60.0 148.5 +/+

VESA, 2048 x 1080 66.58 60.0 147.16 +/-

CVR, 2560 x 1440 88.8 60.0 241.5 + /-

Vertical Frequency

Pixel Clock (MHz)

Sync Polarity (Horizontal/

12 | About Your Monitor

DP MST Multi-Stream Transport (MST) Modes

U2421HE

MST Source Monitor Maximum number of external monitors that can be

1920 x 1080/60 Hz 3

NOTE: Maximum external monitor resolution supported is 1920 x 1080 60 Hz only.

supported

1920 x 1080/60 Hz

U2721DE

MST Source Monitor Maximum number of external monitors that can be

2560 x 1440/60 Hz 1

NOTE: Maximum external monitor resolution supported is 2560 x 1440 60 Hz only.

supported

2560 x 1440/60 Hz

USB-C MST Multi-Stream Transport (MST) Modes

U2421HE

OSD Dislay Info: Link rate(current)

HBR3 2

HBR2 1

U2721DE

OSD Dislay Info: Link rate(current)

HBR3 (High Resolution) 1

HBR3 (High Data Speed) 0

HBR2 (High Resolution) 1

HBR2 (High Data Speed) 0

Maximum number of external monitors that can be supported

1920 x 1080/60 Hz

Maximum number of external monitors that can be supported

2560 x 1440/60 Hz

About Your Monitor | 13

Electrical Specifications

Model U2421HE/U2721DE

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

Input voltage/ frequency/current 100-240 VAC / 50 or 60 Hz ± 3 Hz / 1.8 A (maximum) Inrush current 120 V: 30 A (Max.)

Per dierential line at 100 ohm impedance

•DP/USB Type-C signal input support

240 V: 60 A (Max.)

Physical Characteristics

Model

Connector type •DP connector (include DP

Signal cable type DP to DP 1.8 M cable

Dimensions (with stand)

Height (extended)

Height (compressed)

Width

Depth

Dimensions (without stand)

Height

Width

Depth

Stand dimensions

Height (extended)

Height (compressed)

U2421HE U2721DE

in and DP out)

•HDMI connector

•USB Type-C connector

•Audio line-out

•RJ45 connector

•USB 3.0 downstream port

connector x 4

(Port with icon supports BC 1.2.)

USB Type-C 1.0 M cable

478.4 mm (18.84 in.) 520.2 mm (20.48 in.)

348.4 mm (13.72 in.) 390.2 mm (15.36 in.)

538.5 mm (21.20 in.) 612.2 mm (24.10 in.)

165.0 mm (6.50 in.) 180.0 mm (7.09 in.)

313.7 mm (12.35 in.) 355.0 mm (13.98 in.)

538.5 mm (21.20 in.) 612.2 mm (24.10 in.)

39.0 mm (1.54 in.) 39.0 mm (1.54 in.)

393.5 mm (15.49 in.) 413.6 mm (16.28 in.)

347.0 mm (13.66 in.) 367.1 mm (14.45 in.)

battery

•DP connector (include DP in and DP out)

•HDMI connector

•USB Type-C connector

•Audio line-out

•RJ45 connector

•USB 3.0 downstream port

connector x 4

(Port with icon supports BC 1.2.)

DP to DP 1.8 M cable USB Type-C 1.0 M cable

battery

14 | About Your Monitor

Width

Depth

Weight

Weight with packaging 7.55 kg (16.64 lb) 8.72 kg (19.22 lb)

Weight with stand assembly and cables

Weight without stand assembly (For wall mount or VESA mount considerations

- no cables) Weight of stand assembly 1.59 kg (3.50 lb) 1.72 kg (3.79 lb)

218.0 mm (8.58 in.) 230.0 mm (9.06 in.)

165.0 mm (6.50 in.) 180.0 mm (7.09 in.)

5.32 kg (11.73 lb) 6.24 kg (13.75 lb)

3.37 kg (7.43 lb) 4.19 kg (9.23 lb)

Environmental Characteristics

Model U2421HE/U2721DE

Compliant Standards

•ENERGY STAR certified Monitor.

•EPEAT registered where applicable. EPEAT registration varies by country.

See www.epeat.net for registration status by country.

•TCO Certified Display.

•RoHS Compliant.

•BFR/PVC Free monitor (excluding external cables).

•Meets NFPA 99 leakage current requirements.

•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 5,000 m (16,404 ft) (maximum)

Non-operating 12,192 m (40,000 ft) (maximum)

Thermal dissipation

U2421HE 478.02 BTU/hour (maximum)

59.75 BTU/hour (typical)

U2721DE 546.30 BTU/hour (maximum)

113.36 BTU/hour (typical)

About Your Monitor | 15

Power Management Modes

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 power save mode*. If the computer detects input from the keyboard, mouse, or other input devices, the monitor automatically resumes functioning. The following table shows the power consumption and signaling of this automatic power saving feature.

U2421HE

VESA Modes

Normal operation

Active-off mode

Horizontal Sync

Vertical Sync

Video Power Indicator Power Consumption

Active Active Active White 140 W (maximum)**

17.5 W (typical)

Inactive Inactive Off White

Less than 0.3 W

(Glowing)

Switch off - - - Off Less than 0.3 W

Power Consumption P

12.87 W

Total Energy Consumption (TEC) 43.56 kWh

U2721DE

VESA Modes

Normal operation

Active-off mode

Horizontal Sync

Vertical Sync

Video Power Indicator Power Consumption

Active Active Active White 160 W (maximum)**

33.2 W (typical)

Inactive Inactive Off White

Less than 0.3 W

(Glowing)

Switch off - - - Off Less than 0.3 W

Power Consumption P

19.9 W

Total Energy Consumption (TEC) 64.3 kWh

16 | About Your Monitor

The OSD operates only in the normal operation mode. If you press any button in the activeoff mode, the following message is displayed:

Dell UltraSharp 24/27 Monitor

No DP signal from your device.

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

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

input source.

U2421HE/U2721DE

*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, and USB active.

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

NOTE:

: 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.

About Your Monitor | 17

Pin Assignments

DP port (in)

Pin number 20-pin side of theconnected signal cable

1 ML3(n)

2 GND

3 ML3(p)

4 ML2(n)

5 GND

6 ML2(p)

7 ML1(n)

8 GND

9 ML1(p)

10 ML0(n)

11 GND

12 ML0(p)

13 CONFIG1

14 CONFIG2

15 AUX CH (p)

16 GND

17 AUX CH (n)

18 Hot Plug Detect

19 Return

20 DP_PWR

18 | About Your Monitor

DP port (out)

Pin number 20-pin side of theconnected signal cable

1 ML0(p)

2 GND

3 ML0(n)

4 ML1(p)

5 GND

6 ML1(n)

7 ML2(p)

8 GND

9 ML2(n)

10 ML3(p)

11 GND

12 ML3(n)

13 CONFIG1

14 CONFIG2

15 AUX CH(p)

16 GND

17 AUX CH(n)

18 Hot Plug Detect

19 Return

20 DP_PWR

About Your Monitor | 19

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

20 | About Your Monitor

USB Type-C port

Pin Signal Pin Signal

A1 GND B12 GND

A2 SSTXp1 B11 SSRXp1

A3 SSTXn1 B10 SSRXn1

A4 VBUS B9 VBUS

A5 CC1 B8 SBU2

A6 Dp1 B7 Dn1

A7 Dn1 B6 Dp1

A8 SBU1 B5 CC2

A9 VBUS B4 VBUS

A10 SSRXn2 B3 SSTXn2

A11 SSRXp2 B2 SSTXp2

A12 GND B1 GND

About Your Monitor | 21

Universal Serial Bus (USB)

This section gives you information about the USB ports available on your monitor.

NOTE: Up to 2 A on USB downstream port (port with battery icon) with BC 1.2

compliance devices; up to 0.9 A on the other 2 USB downstream ports.

Your computer has the following USB ports:

• 4 downstream - 2 at left side, 2 at bottom

Power Charging Port - the ports with charging capability if the device is BC 1.2 compatible.

NOTE: The monitor’s USB ports work only when the monitor is on or in the power save

mode. In power save mode, if the USB cable (Type-C to Type-C) is plugged in, the USB ports can work normally. Otherwise, follow the OSD setting of USB, if the setting is “On During Standby” then USB work normally, otherwise USB is disabled. If you turn off the monitor and then turn it on, the attached peripherals may take a few seconds to resume normal functionality.

battery icon supports fast current

Transfer speed Data rate Maximum power consumption

SuperSpeed 5 Gbps 4.5 W

Hi-Speed 480 Mbps 2.5 W

Full speed 12 Mbps 2.5 W

(each port)

USB downstreamport

Pin number Signal

1 VBUS

2 D-

3 D+

4 GND

5 StdA_SSRX-

6 StdA_SSRX+

7 GND_DRAIN

8 StdA_SSTX-

9 StdA_SSTX+

Shell Shield

22 | About Your Monitor

RJ45 port (connector side)

PHY SIDE

CABLE SIDE

RJ45

GREEN

ORANGE

SHIELD

GROUND

2kV, 1000pF

Pin Signal Pin Signal

1 TD1 + 8 TD3 -

2 TD1 - 9 TD4 +

3 TD2 + 10 TD4 -

4 TD2 - 11

5 CT 12

6 CT 13 GREEN

7 TD3 + 14 GREEN

Support OS

OS Version

Windows Win7 (LAN driver V7.48)

Win8, 8.1 (LAN driver V8.55)

Win10 (LAN driver V10.34)

Linux OS(Chorms, Android, Other Linux based OS)

macOS V10.6 to V10.15 (LAN driver V1.0.20)

Network (RJ45) data rate via USB-C at:

1). video priority: 480 Mbps

2). data priority: 1000 Mbps

NOTE: This LAN port is 1000Base-T IEEE 802.3az compliant, supporting Mac Address

Pass-thru and Wake-on-LAN (WOL) from standby (S3 only) mode. It also supports PXE Boot function, include UEFI PXE and Legacy PXE.

The Linux OS base on kernel version support to V4.15 or before (LAN driver V2.12.0)

GREEN_ORANGE

About Your Monitor | 23

Plug-and-Play

You can install the monitor in any Plug-and-Play-compatible system. The monitor automatically provides the computer system 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 can select different settings if desired. 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 on LCD Monitor Pixel Policy, see Dell support site at: www.dell.com/support/monitors.

24 | About Your Monitor

Setting Up the Monitor

Attaching the Stand

NOTE: The stand riser and stand base are detached when the monitor is shipped

from the factory.

NOTE: The procedure below is applicable for the default stand. If you purchased

any other stand, see the documentation shipped with the stand to set it up.

CAUTION: Place monitor of a flat, clean, and soft surface to avoid scratching the

display panel.

To attach the monitor stand:

1 Align the stand base protruded blocks to the matching slot on the stand.

2 Insert the stand base blocks fully into the stand slot.

3 Lift the screw handle and turn the screw clockwise.

4 After fully tightening the screw, fold the screw handle flat within the recess.

Setting Up the Monitor | 25

1 Remove the monitor protective cover and place the monitor with its front facing

downward on it.

2 Insert the two tabs on the upper part of the stand to the groove on the back of

the monitor.

3 Press the stand down till it snaps into its place.

26 | Setting Up the Monitor

Using the Tilt, Swivel, and Vertical Extension

NOTE: This is applicable for a monitor with a stand. If you purchased any other

stand, refer to the respective stand setup guide for set up instructions.

Tilt, Swivel and Vertical Extension

With the stand attached to the monitor, you can tilt the monitor for the most comfortable viewing angle.

5°

40°

130 mm

21°

40°

NOTE: The stand is detached when the monitor is shipped from the factory.

Rotating the Monitor

Before you rotate the monitor, your monitor should be fully vertically extended and fully tilted up to avoid hitting the bottom edge of the monitor.

90°

NOTE: To use the Display Rotation function (Landscape versus Portrait view) with

your Dell computer, you require an updated graphics driver that is not included with this monitor. To download the graphics driver, go to www.dell.com/support and see the Download section for Video Drivers for latest driver updates.

NOTE: When in the Portrait View Mode, you may experience performance degradation

in graphic-intensive applications (3D Gaming and etc.).

Setting Up the Monitor | 27

Adjusting the Rotation Display Settings of Your System

After you have rotated your monitor, you need to complete the procedure below to adjust the Rotation Display Settings of your System.

NOTE: If you are using the monitor with a non-Dell computer, you need to go the

graphics driver website or your computer manufacturer website for information on rotating the ’contents’ on your display.

To adjust the Rotation Display Settings:

1 Right-click on the desktop and click Properties. 2 Select the Settings tab and click Advanced.

If you have an AMD graphics card, select the Rotation tab and set the preferred

rotation.

If you have an nVidia graphics card, click the nVidia tab, in the left-hand column

select NVRotate, and then select the preferred rotation.

If you have an Intel® graphics card, select the Intel graphics tab, click Graphic

Properties, select the Rotation tab, and then set the preferred rotation.

NOTE: If you do not see the rotation option or it is not working correctly, go to

www.dell.com/support and download the latest driver for your graphics card.

28 | Setting Up the Monitor

Connecting Your Monitor

WARNING: Before you begin any of the procedures in this section, follow the

Safety Instructions.

To connect your monitor to the computer:

1 Turn o your computer.

2 Connect the DP/USB type-C cable from your monitor to thecomputer. 3 Switch on your monitor.

4 Select the correct input source at monitor OSD Menu and turn on your computer.

NOTE: U2421HE/U2721DE default setting is DP 1.4. A DP 1.1 Graphic card

may not display normally. Please refer to “product specific problems – No image when

using DP connection to the PC” to change default setting.

Connecting the HDMI cable (Optional)

HDMI

Connecting the DP cable

Setting Up the Monitor | 29

Connecting the monitor for DP Multi-Stream Transport (MST) function

NOTE: Supports the DP MST feature. To make use of this feature, your PC

Graphics Card must be certified to DP1.2 with MST option.

NOTE: Remove the rubber plug when using DP out connector.

DP out

Connecting the USB Type-C cable

USB Type-C

The USB Type-C port on your monitor:

• Can be used as USB Type-C or DisplayPort 1.4, alternatively.

• Supports USB Power Delivery (PD), with profiles up to 65 W.

NOTE: Regardless of the power requirement/actual power consumption of your laptop,

or the remaining power runtime in your battery, the Dell U2421HE/U2721DE monitor is designed to supply power delivery of up to 65 W to your laptop.

Rated power (on laptops that have USB Type-C with PowerDelivery)

Maximum charging power

45 W 45 W

65 W 65 W

90 W Not supported

130 W Not supported

30 | Setting Up the Monitor

Connecting the monitor for USB-C Multi-Stream Transport (MST) function

USB Type-C

DP in

DP out

USB Type-C

NOTE: The maximum number of supported U2721DE via MST is subjected to the

bandwith of the USB-C source. Please refer to “product specific problems –No image

when using USB-C MST”.

NOTE: Remove the rubber plug when using DP out connector.

Connecting the monitor for RJ45 Cable (Optional)

USB Type-C

RJ45

NOTE: RJ45 cable is non in-box standard accessory.

Setting Up the Monitor | 31

USB Type-C

Organizing Your Cables

After attaching all necessary cables to your monitor and computer, (see Connect-

ing Your Monitor for cable attachment) organize all cables as shown above.

Removing the Monitor Stand

CAUTION: To prevent scratches on the LCD screen while removing the stand,make sure that the monitor is placed on a soft, clean surface.

NOTE: The procedure below is applicable for the default stand. If you purchased

any other stand, see the documentation shipped with the stand to set it up.

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.

32 | Setting Up the Monitor

Wall Mounting (Optional)

U2421HE

NOTE: Use M4 x 10 mm screws to connect the monitor to the wall-mounting kit.

Refer to the instructions that come with the VESA-compatible wall mounting kit. 1 Place the monitor on a soft cloth or cushion on a stable, at table. 2 Remove the stand. 3 Use a Phillips crosshead screwdriver to remove the four screws securing the plastic cover. 4 Attach the mounting bracket from the wall mounting kit to the monitor. 5 Mount the monitor on the wall by following the instructions that comes with the wall mounting kit.

NOTE: For use only with UL or CSA or GS-listed wall mount bracket with minimum

weight/load bearing capacity of 3.37 kg (U2421HE)/4.19 kg (U2721DE).

Setting Up the Monitor | 33

Operating the Monitor

3 4 51 2

Turning on the Monitor

Press the button to turn on the monitor.

Using the Front Panel Controls

Use the control buttons at the bottom edge of the monitor to adjust the characteristics of the image being displayed. As you use these buttons to adjust the controls, an OSD shows the numeric values of the characteristics as they change.

34 | Operating the Monitor

The following table describes the front panel buttons:

Front-Panel Button Description

Shortcut key: Preset Modes

Shortcut key:

Input Source

Exit

Power (with power light

indicator)

Use this button to choose from a list of preset colormodes.

Use this button to choose from a list of Input Source.

Use this menu button to launch the on-screen display (OSD) and select the OSD menu.

See Accessing the Menu System.

Use this button to go back to the main menu or exit the OSD main menu.

Use the Power button to turn the monitor On and Off. The white LED indicates the monitor is On and fully functional.

A glowing white LED indicates DPMS Power Save Mode.

Operating the Monitor | 35

Using the OSD Lock function

With the control buttons on the monitor locked, you can prevent people from accessing the controls. It also prevents accidental activation in multiple monitors side-by-side setup.

Dell UltraSharp 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Personalize

Others

1. The following message will appear:

Dell UltraSharp 24/27 Monitor

Are you sure you want to lock the Menu Buttons?

To unlock the Buttons, refer to the User’s Guide.

2. Select ‘Yes‘ to Lock the buttons, the following table describes the control icons:

Language

Rotation

Transparency

Timer

Lock

Reset Menu Power Button

Yes No

Menu Buttons

Menu + Power Buttons

Disable

U2421HE/U2721DE

Options Description

Use this icon to lock OSD menu function.

Menu Buttons lock

Use this icon to lock power button from powering off.

Power button lock

Use this icon to lock OSD menu and power button from powering off.

Menu and Power buttons lock

36 | Operating the Monitor

Options Description

Built-in Diagnostics

Use this icon to run the built-in diagnostics, see Built-in

Diagnostics.

3. Hold

Options Description

for 4 seconds, Select the following table describes the unlock icons:

Use this icon to unlock OSD menu function.

Menu Buttons lock

Use this icon to unlock power button from powering off.

Power button lock

Use this icon to unlock OSD menu and power button from powering off.

Menu and Power buttons lock

Operating the Monitor | 37

Front-Panel Button

2 31

Use the buttons on the front of the monitor to adjust the image settings.

Front Panel Button Description

Up Down

Use the Up (increase) and Down (decrease) keys to adjust items in the OSD menu.

Use the OK button to confirm your selection.

Use the Back button to go back to the previous menu.

Back

38 | Operating the Monitor

Using the On-Screen Display (OSD) Menu

Accessing the Menu System

NOTE: Any changes you make using the OSD menu are automatically saved if

youmove to another OSD menu, exit the OSD menu, or wait for the OSD menu todisappear.

1 Press the

Dell UltraSharp 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Personalize

Others

button to launch the OSD menu and display the main menu.

75 %

2 Press the and buttons to move between options. As you move from one

icon to another, the option name is highlighted.

3 Press the

4 Press the

5 Press

or or button once to activate the highlighted option.

and buttons to select the desired parameter.

to enter the slide bar and then use the or button, according to the

indicators on the menu, to make your changes.

6 Select the

to return to previous menu or to accept and return to previous

menu.

Operating the Monitor | 39

Icon Menu and

Submenus

Brightness/ Contrast

Brightness Brightness adjusts the luminance of the backlight

Description

Use this menu to activate Brightness/Contrast adjustment.

Dell UltraSharp 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Personalize

Others

75 %

(minimum 0; maximum 100).

Press the

button to increase brightness.

button to decrease brightness.

Contrast Adjust the Brightness first, and then adjust Contrast only if

further adjustment is necessary.

Press the

button to increase contrast and press the button to decrease contrast (between 0 and 100).

Contrast adjusts the difference between darkness and lightness on the monitor.

Input Source Use the Input Source menu to select between different

video inputs that are connected to your monitor.

Dell UltraSharp 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Personalize

Others

USB Type-C

HDMI

Auto Select

Auto Select for USB-C

Reset Input Source

Prompt for Multiple Inputs

40 | Operating the Monitor

Icon Menu and

Submenus

USB Type-C Select USB Type-C input when you are using the USB Type-C

DP Select DP input when you are using the DP (DisplayPort)

HDMI Select HDMI input when you are using the HDMI connector.

Auto Select

Auto Select for USB-C

Reset Input Source

Color Use the Color menu to adjust the color setting mode.

Description

connector.

to select the USB Type-C input source.

Use

connector.

Use

to select the DP input source.

Use

to select the HDMI input source.

Use

to select Auto Select, the monitor scans for available

input sources.

Allows you to set Auto Select for USB Type-C to:

•Prompt for Multiple Inputs : always show Switch to USB Type-C Video Input message for user to choose whether to switch or not.

•Yes: The monitor always switch to USB Type-C video without asking while USB Type-C connected.

•No: The monitor will NOT auto switch to USB Type-C video from another available input.

Resets your monitor’s Input Source settings to the factory defaults.

Dell UltraSharp 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Personalize

Others

Preset Modes

Input Color Format

Reset Color

Standard

RGB

Operating the Monitor | 41

Icon Menu and

Submenus

Preset Modes When you select Preset Modes, you can choose Standard,

Description

ComfortView, Multiscreen Match, Movie, Game, Color Temp. or Custom Color from the list.

Dell UltraSharp 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Personalize

Others

Preset Modes

Input Color Format

Reset Color

Standard

ComfortView

Multiscreen Match

Movie

Game

Color Temp.

Custom Color

•Standard: Default color settings. This is the default preset

mode.

•ComfortView: Decreases the level of blue light emitted from

the screen to make viewing more comfortable for your eyes. NOTE: To reduce the risk of eye strain and neck/arm/back/

shoulders pain from using the monitor for long periods of time, we suggest you to :

• Set the screen about 20 to 28 in. (50-70 cm) from your eyes.

• Blink frequently to moisten or rewet your eyes when working

with the monitor.

• Take regular and frequent breaks for 20 minutes every two hours.

• Look away from your monitor and gaze at a distant object at 20 feet away for at least 20 seconds during the breaks.

• Perform stretches to relieve tension in the neck/arm/back/ shoulders during the breaks.

•Multiscreen Match: Option to allow matching of the white backgrounds on multiple monitors.

•Movie: Ideal for movies.

•Game: Ideal for most gaming applications.

•Color Temp.: The screen appears warmer with a red/yellow tint

with slider set at 5,000K or cooler with blue tint with slider set at 10,000K.

•Custom Color: Allows you to manually adjust the color settings. Press the

and buttons to adjust the Red, Green, and

Blue values and create your own preset color mode.

42 | Operating the Monitor

Icon Menu and

Submenus

Input Color Format

Description

Allows you to set the video input mode to:

•RGB: Select this option if your monitor is connected to a computer (or DVD player) using the USB Type-C, DP cable. YPbPr: Select this option if your DVD player supports only YPbPr output.

Dell UltraSharp 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Personalize

Others

Preset Modes

Input Color Format

Reset Color

RGB

YPbPr

Hue

Use or to adjust the hue from 0 to 100.

NOTE: Hue adjustment is available only for Movie and Game mode.

Saturation

Use

or to adjust the saturation from 0 to 100.

NOTE: Saturation adjustment is available only for Movie and Game mode.

Reset Color Resets your monitor’s color settings to the factory defaults.

Operating the Monitor | 43

Icon Menu and

Submenus

Display Use the Display menu to adjust image.

Aspect Ratio Adjust the image ratio to Wide 16:9, Auto Resize, 4:3, 1:1.

Sharpness Makes the image look sharper or softer.

Response Time

MST DP Multi Stream Transport, Set to ON enables MST(DP out), Set

USB-C Prioritization

(U2721DE only)

Reset Display Restores the display settings to factory defaults.

Description

Dell UltraSharp 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Personalize

Others

or to adjust the sharpness from ‘0’ to ‘100’.

Use

Aspect Ratio

Sharpness 50

Response Time Normal

MST

USB-C Prioritization

Reset Display

Wide 16:9

O

High Resolution

Allows you to set the Response Time to Normal or Fast.

to OFF disables MST function.

NOTE: When DP/USB Type-C upstream cable and DP downstream cable is connected, monitor will set MST = ON automatically, this action will only be done once after Factory Reset or Display Reset.

High Resolution: High Resolution can match two monitors with 2560 x 1440 resolution.

NOTE: High Resolution is available only for MST ON. This is default setting. 4 Lane DP only for USB 2.0 input, no USB 3.0.

High data speed: High data speed is for 2 Lane DP USB3.0.

44 | Operating the Monitor

Icon Menu and

Submenus

Menu Select this option to adjust the settings of the OSD, such as the

Language Set the OSD display to one of eight languages.

Rotation Rotates the OSD by 0/90/180/270 degrees.

Transparency

Timer OSD Hold Time: Sets the length of time the OSD remains active

Description

languages of the OSD, the amount of time the menu remains on screen, and so on.

Dell UltraSharp 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Personalize

Others

Language

Rotation

Transparency

Timer

Lock

Reset Menu

English

20 s

Disable

(English, Spanish, French, German, Brazilian Portuguese, Russian, Simplified Chinese, or Japanese).

You can adjust the menu according to your display rotation.

Select this option to change the menu transparency by using

and (min. 0 / max. 100).

after you press a button.

Use the

and buttons to adjust the slider in 1-second

increments, from 5 to 60 seconds.

Operating the Monitor | 45

Icon Menu and

Submenus

Lock Controls user access to adjustments. the buttons are locked.

Reset Menu

Description

Dell UltraSharp 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Personalize

Others

Language

Rotation

Transparency

Timer

Lock

Reset Menu Power Button

Menu Buttons

Menu + Power Buttons

Disable

•Menu Buttons: Through OSD to lock the Menu buttons.

•Power Button: Through OSD to lock the Power button.

•Menu + Power Buttons: Through OSD to lock the all of Menu

and Power buttons.

•Disable: Press and hold the

button on the left of the power

button for 4 sec.

Restore the menu settings to factory defaults.

46 | Operating the Monitor

Icon Menu and

Submenus

Personalize

Description

Dell UltraSharp 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Personalize

Others

Shortcut Key 1

Shortcut Key 2

Power Button LED

USB-A Charging

USB-C Charging

Reset Personalization

Preset Modes

Brightness/Contrast

On During Active

O During Standby

O During Power O

Shortcut key 1

Shortcut key 2

Power Button LED

USB-A Charging

USB-C Charging

Reset Personalization

Select from Preset Modes, Brightness/Contrast, Input Source, Aspect Ratio, Rotation set as shortcut key 1.

Select from Preset Modes, Brightness/Contrast, Input Source, Aspect Ratio, Rotation set as shortcut key 2.

Allows you to set the state of the power light to save energy.

Allows you to enable or disable USB Type-A (Downstream Ports) charging function during monitor standby mode.

NOTE: This option is only available when the USB Type-C (Upstream Port) cable is unplugged. If the USB Type-C cable is connected, USB-A Charging follows the USB host power status and the option is not accessible.

NOTE: This option was previously called “USB” in older monitor firmware revisions.

Allows you to enable or disable Always On USB Type-C Charging function during monitor Power Off mode.

Restores shortcut keys to factory defaults.

Operating the Monitor | 47

Icon Menu and

Submenus

Others

Display Info Displays the monitor’s current settings.

DDC/CI DDC/CI (Display Data Channel/Command Interface) allows you

Description

Dell UltraSharp 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Personalize

Others

Display Info

DDC/CI

LCD Conditioning

Firmware

Service Tag

Reset Others

Factory Reset ENERGY STAR

O

M2T101

H8CJ2NF

Select this option to adjust the OSD settings suchas the DDC/CI, LCD conditioning, and so on.

to adjust the monitor settings using software on your computer.

Select Off to turn off this feature.

Enable this feature for best user experience and optimum performance of your monitor.

Dell UltraSharp 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Personalize

Others

Display Info

DDC/CI

LCD Conditioning

Firmware

Service Tag

Reset Others

Factory Reset

O

48 | Operating the Monitor

Icon Menu and

Submenus

LCD Conditioning

Description

Helps reduce minor cases of image retention. Depending on the degree of image retention, the program may take some time to run. Select On to start the process.

Dell UltraSharp 24/27 Monitor

Brightness/Contrast

Input Source

Color

Display

Personalize

Others

Display Info

DDC/CI

LCD Conditioning

Firmware

Service Tag

Reset Others

Factory Reset

O

Firmware

Firmware version.

Service Tag Displays the Service Tag. The Service Tag is a unique

alphanumeric identifier that allows Dell to identify the product specifications and access warranty information.

NOTE: The Service Tag is also printed on a label located at the back of the cover.

Reset Others Restores other settings, such as DDC/CI, to factorydefaults.

Factory Reset

Restores all preset values to the factory default settings. These are also the settings for ENERGY STAR

Dell UltraSharp 24 Monitor

Brightness/Contrast

Input Source

Color

Display

Personalize

Others

Display Info

DDC/CI

LCD Conditioning

Firmware

Service Tag

Reset Others

Factory Reset

tests.

O

M2T101

H8CJ2NF

ENERGY STAR

Operating the Monitor | 49

OSD Warning Messages

When the monitor does not support a particular resolution mode, you can see the following message:

U2421HE

Dell UltraSharp 24 Monitor

The current input timing is not supported by the monitor display. Please

change your input timing to

listed timing as per the monitor speciﬁcations.

Dell UltraSharp 27 Monitor

The current input timing is not supported by the monitor display. Please

change your input timing to

listed timing as per the monitor speciﬁcations.

This means that the monitor cannot synchronize with the signal that it is receiving from the computer. See Monitor Specifications for the Horizontal and Vertical frequency ranges addressable by this monitor. Recommended mode is 1920 x 1080 (U2421HE) / 2560 x 1440 (U2721DE).

1920x1080, 60Hz or any other monitor

U2421HE

U2721DE

2560x1440, 60Hz or any other monitor

U2721DE

You can see the following message before the DDC/CI function is disabled:

Dell UltraSharp 24/27 Monitor

The function of adjusting display setting using PC

application will be disabled.

Do you wish to disable DDC/CI function?

Yes No

U2421HE/U2721DE

50 | Operating the Monitor

When the monitor enters the Power Save mode, the following message will appear:

Dell UltraSharp 24/27 Monitor

Entering Power Save Mode.

U2421HE/U2721DE

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

If you press any button other than the power button, the following messages will appear depending on the selected input:

Dell UltraSharp 24/27 Monitor

No DP signal from your device.

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

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

input source.

U2421HE/U2721DE

If either DP, USB Type-C input is selected and the corresponding cable is not connected, a floating dialog box as shown below appears.

Dell UltraSharp 24/27 Monitor

No DP Cable

The display will go into Power Save Mode in 4 minutes.

www.dell.com/support/U2421HE www.dell.com/support/U2721DE

Dell UltraSharp 24/27 Monitor

No USB Type-C Cable

The display will go into Power Save Mode in 4 minutes.

www.dell.com/support/U2421HE www.dell.com/support/U2721DE

U2421HE/U2721DE

Operating the Monitor | 51

A message is displayed while the cable supporting DP alternate mode is connected to the monitor under the following conditions:

• When Auto Select for USB-C is set to Prompt for Multiple Inputs.

• When the DP cable is connected to the monitor.

Dell UltraSharp 24/27 Monitor

Switch to USB-C Video Input:

Yes

U2421HE/U2721DE

When you select OSD items of High resolution in Display feature, the following message will appear:

Dell UltraSharp 27 Monitor

If your PC is not DP 1.4, this option will result in reduced screen performance.

Please disconnect any USB storage device to your monitor during

the switching process (up to 12 seconds).

Do you want to continue?

Yes No

U2721DE

When you select OSD items of High Data Speed in Display feature, the following message will appear:

Dell UltraSharp 27 Monitor

Please disconnect any USB storage device to your monitor during

the switching process (up to 12 seconds).

Do you want to continue?

Yes No

U2721DE

52 | Operating the Monitor

When USB-C Prioritization is set to High Data Speed, select OSD items of Factory Reset in Other feature, the following message will appear:

Dell UltraSharp 27 Monitor

Please disconnect any USB storage device to your monitor during

the switching process (up to 12 seconds).

Are you sure you want to reset to default settings?

Yes

U2721DE

When you select OSD items of Factory Reset in Other feature, the following message will appear:

Dell UltraSharp 24/27 Monitor

Are you sure you want to reset to default settings?

Yes No

U2421HE/U2721DE

When you select ‘Yes‘ to reset to default settings, the following message will appear:

Dell UltraSharp 24/27 Monitor

Easy Initial Setup:

Select ‘Yes’ to enable the following function(s):

•

Always on USB -C Charging

Yes No

When ‘Yes’ is select, power consumption may increase.

When ‘No’ is selected, it will comply with ENERGY STAR requirements.

Individual settings can be changed in the Menu.

U2421HE/U2721DE

See Troubleshooting for more information.

Operating the Monitor | 53

Troubleshooting

WARNING: Before you begin any of the procedures in this section, follow the

Safety Instructions.

Self-Test

Your monitor provides a self-test feature that allows you to check whether your monitor is functioning properly. If your monitor and computer are properly connected but the monitor screen remains dark, run the monitor self-test by performing the following steps:

1 Turn o both your computer and the monitor.

2 Unplug the video cable from the back of the computer. To ensure proper Self-Test operation, remove all digital and the analog cables from the back of computer. 3 Turn on the monitor.

The floating dialog box should appear on-screen (against a black background), if the monitor cannot sense a video signal and is working correctly. While in self-test mode, the power LED remains white. Also, depending upon the selected input, one of the dialogs shown below will continuously scroll through the screen.

Dell UltraSharp 24/27 Monitor

No DP Cable

The display will go into Power Save Mode in 4 minutes.

www.dell.com/support/U2421HE www.dell.com/support/U2721DE

U2421HE/U2721DE

Dell UltraSharp 24/27 Monitor

No USB Type-C Cable

The display will go into Power Save Mode in 4 minutes.

www.dell.com/support/U2421HE www.dell.com/support/U2721DE

U2421HE/U2721DE

4 This box also appears during normal system operation if the video cable becomes disconnected or damaged.

5 Turn o your monitor and reconnect the video cable; then turn on both your computer and the monitor.

If your monitor screen remains blank after you use the previous procedure, check your video controller and computer, because your monitor is functioning properly.

54 | Troubleshooting

Built-in Diagnostics

3 4 51 2

Your monitor has a built-in diagnostic tool that helps you determine if the screen abnormality you are experiencing is an inherent problem with your monitor, or with your computer and video card.

NOTE: You can run the built-in diagnostics only when the video cable is unplugged

and the monitor is in self-test mode.

To run the built-in diagnostics: 1 Make sure that the screen is clean (no dust particles on the surface of the screen).

2 Unplug the video cable(s) from the back of the computer or monitor. The monitor

then goes into the self-test mode.

3 Press and hold Button 1 for 5 seconds. A gray screen appears.

4 Carefully inspect the screen for abnormalities.

5 Press Button 1 on the front panel again. The color of the screen changes to red.

6 Inspect the display for any abnormalities.

7 Repeat steps 5 and 6 to inspect the display in green, blue, black, white, and text

screens.

The test is complete when the text screen appears. To exit, press Button 1 again. If you do not detect any screen abnormalities upon using the built-in diagnostic tool, the monitor is functioning properly. Check the video card and computer.

Troubleshooting | 55

Common Problems

The following table contains general information about common monitor problems you might encounter and the possible solutions:

Common Symptoms

No Video/Power LED off

No Video/Power LED on

Missing Pixels LCD screen has

Stuck-on Pixels LCD screen has

Brightness Problems

Safety Related Issues

Intermittent Problems

What You Experience

No picture •Ensure that the video cable connecting the monitor

No picture or no brightness

spots

bright spots

Picture too dim or too bright

Visible signs of smoke or sparks

Monitor malfunctions on & off

Possible Solutions

and the computer is properly connected and secure.

•Verify that the power outlet is functioning properly using any other electrical equipment.

•Ensure that the power button is depressed fully.

•Ensure that the correct input source is selected in

the Input Source menu.

•Increase brightness and contrast controls via OSD.

•Perform monitor self-test feature check.

•Check for bent or broken pins in the video cable

connector.

•Run the built-in diagnostics.

•Ensure that the correct input source is selected in

the Input Source menu.

•Cyclepoweron-off.

•Pixelthatispermanentlyoffisanaturaldefect

that can occur in LCD technology.

•FormoreinformationonDellMonitorQuality

and Pixel Policy, see Dell Support site at: www.dell.com/support/monitors.

•CyclepowerOn-Off.

•Pixelthatispermanentlyoffisanaturaldefect

that can occur in LCD technology.

•FormoreinformationonDellMonitorQuality

and PixelPolicy, see Dell Support site at: www.dell.com/support/monitors.

•Reset the monitor to factory settings.

•Adjust brightness and contrast controls via OSD.

•Do not perform any troubleshooting steps.

•Contact Dell immediately.

•Ensure that the video cable connecting the monitor

to the computer is connected properly and is secure.

•Resetthemonitortofactorysettings.

•Perform monitor self-test feature check to

determine if the intermittent problem occurs in selftest mode.

56 | Troubleshooting

Common Symptoms

Missing Color Picture missing

Wrong Color Picture color not

Image retention from a static image left on the monitor for a long period of time

What You Experience

color

good

Faint shadow from the static image displayed appears on the screen

Possible Solutions

•Perform monitor self-test.

•Ensure that the video cable connecting the monitor

to the computer is connected properly and is secure.

•Check for bent or broken pins in the video cable connector.

•Change the settings of the Preset Modes in the Color menu OSD depending on the application.

•Adjust R/G/B value under Custom Color in Color menu OSD.

•Change the Input Color Format to PC RGB or YPbPr in the Color menu OSD.

•Run the built-in diagnostics.

•Use the Power Management feature to turn o

the monitor at all times when not in use (for more information, see Power Management Modes).

•Alternatively, use a dynamically changing screensaver.

Product Specific Problems

Problem What you

Screen image is too small

Cannot adjust the monitor with the buttons on the front panel

No Input Signal when user controls are pressed

experience

Image is centered on screen, but does not fill entire viewing area

OSD does not appear on the screen

No picture, the LED light is white

Possible solutions

•Check the Aspect Ratio setting in the Display menu OSD.

•Reset the monitor to factory settings.

•Turn o the monitor, unplug the monitor power

cable, plug it back, and then turn on the monitor.

•Check the signal source. Ensure the computer is not in the power saving mode by moving the mouse or pressing any key on the keyboard.

•Check whether the signal cable is plugged in properly. Connect the signal cable again, if necessary.

•Reset the computer or video player.

Troubleshooting | 57

Problem What you

The picture does not fill the entire screen

No image when using USB Type-C connection to computer, laptop, and so on

No charging when using USB Type-C connection to computer, laptop, and so on

Intermittent charging when using USB Type-C connection to computer,

laptop, and so on

No image when using DP connection to the PC

No image when using USB Type-C MST

No network connection

experience

The picture cannot fill the height or width of the screen

Black screen •Verify if the USB Type-C interface of the device can

No charging •Verify if the device can support one of 5 V/9 V/15

Intermittent charging

Black screen •Verify which DP standard (DP 1.1a or DP 1.4) is your

Black screen or

2nd DUT is not Prime mode

Network dropped or Intermittent

Possible solutions

•Due to dierent video formats (aspect ratio) of DVDs, the monitor may display in full screen.

•Run the built-in diagnostics.

support DP alternate mode.

•Verify if the device required more than 65 W power charging.

•USB Type-C interface of device cannot support DP alternate mode.

•Set Windows to Projection mode.

•Ensure that the USB Type-C cable is not damaged.

V/20 V charging proles.

•Verify if the Notebook requires a >65 W power adaptor.

•If the Notebook requires a >65 W power adaptor, it may not charge with the USB Type-C connection.

•Ensure that you use only Dell approved adapter or the adapter that comes with the product.

•Ensure that the USB Type-C cable is not damaged.

•Check if the maximum power consumption of

device is over 65 W.

•Ensure that you use only Dell approved adapter or the adapter that comes with the product.

•Ensure that the USB Type-C cable is not damaged.

Graphics Card certied to. Download and install the latest graphics card driver.

•Some DP 1.1a graphics card cannot support

DP 1.4 monitors. Go to OSD menu, under Input Source selection, press and hold DP select key for 8 sec to change the monitor setting from DP 1.4 to DP 1.1a.

•USB Type-C input, Go to OSD menu, under Display Info check the Link Rate is HBR2 or HBR3, if Link Rate is HBR2, suggest to use USB Type-C to DP cable to turn on MST.

•check to ensure data priority is selected in OSD. Do not toggle O/On the power button when network is connected, keeps the power button On.

58 | Troubleshooting

Appendix

Safety Instructions

For displays with glossy bezels the user should consider the placement of the display as the bezel may cause disturbing reflections from surrounding light and bright surfaces.

WARNING: 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.

For information on safety instructions, see the Safety, Environmental, and Regulatory Information (SERI).

FCC Notices (U.S. only) and Other Regulatory Information

For FCC notices and other regulatory information, see the regulatory compliance website located at www.dell.com/regulatory_compliance.

Contacting Dell

NOTE: If you do not have an active Internet connection, you can find contact information on your purchase invoice, packing slip, bill, or Dell product catalog.

Dell provides several online and telephone-based support and service options. Availability varies by country and product, and some services may not be available in your area.

To get online Monitor support content:

See www.dell.com/support/monitors.

To contact Dell for sales, technical support, or customer service issues:

1 Go to www.dell.com/support.

2 Verify your country or region in the Choose A Country/Region drop-down menu

at the bottom-right corner of the page.

3 Click Contact Us next to the country dropdown.

4 Select the appropriate service or support link based on your need.

5 Choose the method of contacting Dell that is convenient for you.

Appendix | 59

Setting Up Your Monitor

Setting Display Resolution to 1920 x 1080 (U2421HE)/ 2560 x 1440 (U2721DE) (maximum)

For best performance, set the display resolution to 1920 x 1080 (U2421HE)/2560 x 1440 (U2721DE) pixels by performing the following steps:

In Windows Vista, Windows 7, Windows 8 or Windows 8.1:

1 For Windows 8 or Windows 8.1 only, select the Desktop tile to switch to classic desktop.

For Windows Vista and Windows 7, skip this step.

2 Right-click on the desktop and click Screen Resolution.

3 Click the Dropdown list of the Screen Resolution and select 1920 x 1080

(U2421HE)/2560 x 1440 (U2721DE).

4 Click OK.

In Windows 10:

1 Right-click on the desktop and click Display Settings.

2 Click Advanced display settings.

3 Click the dropdown list of Resolution and select 1920 x 1080 (U2421HE)/2560 x 1440

(U2721DE).

4 Click Apply.

If you do not see the recommended resolution as an option, you may need to update your graphics driver. Please choose the scenario below that best describes the computer system you are using, and follow the given steps.

Dell computer

1 Go to www.dell.com/support, enter your service tag, and download the latest driver for

your graphics card.

2 After installing the drivers for your graphics adapter, attempt to set the resolution to

1920 x 1080 (U2421HE)/2560 x 1440 (U2721DE) again.

NOTE: If you are unable to set the resolution to 1920 x 1080 (U2421HE)/2560 x 1440

(U2721DE), please contact Dell to inquire about a graphics adapter that supports these

resolutions.

60 | Appendix

Non-Dell computer

In Windows Vista, Windows 7, Windows 8 or Windows 8.1:

1 For Windows 8 or Windows 8.1 only, select the Desktop tile to switch to classic desktop.

For Windows Vista and Windows 7, skip this step.

2 Right-click on the desktop and click Personalization. 3 Click Change Display Settings. 4 Click Advanced Settings. 5 Identify your graphics controller supplier from the description at the top of the window

(e.g. NVIDIA, AMD, Intel etc.).

6 Refer to the graphic card provider website for updated driver (for example,

www.amd.com or www.nvidia.com).

7 After installing the drivers for your graphics adapter, attempt to set the resolution to

1920 x 1080 (U2421HE)/2560 x 1440 (U2721DE) again.

In Windows 10:

1 Right-click on the desktop and click Display Settings.

2 Click Advanced display settings.

3 Click Display adapter properties.

4 Identify your graphics controller supplier from the description at the top of the

window (e.g. NVIDIA, AMD, Intel etc.). 5 Refer to the graphic card provider website for updated driver (for example,

www.amd.com or www.nvidia.com).

6 After installing the drivers for your graphics adapter, attempt to set the resolution to

1920 x 1080 (U2421HE)/2560 x 1440 (U2721DE) again.

NOTE: If you are unable to set the recommended resolution, please contact the manufacturer of your computer or consider purchasing a graphics adapter that supports

the video resolution.

Appendix | 61

Maintenance Guidelines

Cleaning Your Monitor

WARNING: Before cleaning the monitor, unplug the monitor power cable from

the electrical outlet.

CAUTION: Read and follow the Safety Instructions before cleaning the monitor.

For best practices, follow these instructions in the list below while unpacking, cleaning, or handling your monitor:

• To clean your anti-static screen, lightly dampen a soft, clean cloth with water. If possible, use a special screen-cleaning tissue or solution suitable for the anti-static coating. Do not use benzene, thinner, ammonia, abrasive cleaners, or compressed air.

• Use a lightly-dampened, soft cloth to clean the monitor. Avoid using detergent of any kind as some detergents leave a milky film on the monitor.

• If you notice white powder when you unpack your monitor, wipe it off with a cloth.

• Handle your monitor with care as a darker-colored monitor may get scratched and

show white scuff marks more than a lighter- colored monitor.

• To help maintain the best image quality on your monitor, use a dynamically changing screen saver and turn off your monitor when not in use.

62 | Appendix

Dell U2421HE User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

About Your Monitor

Package Contents

Product Features

Identifying Parts and Controls

Monitor Specifications

Plug-and-Play

LCD Monitor Quality and Pixel Policy

Setting Up the Monitor

Attaching the Stand

Using the Tilt, Swivel, and Vertical Extension

Adjusting the Rotation Display Settings of Your System

Connecting Your Monitor

Organizing Your Cables

Removing the Monitor Stand

Wall Mounting (Optional)

Operating the Monitor

Turning on the Monitor

Using the Front Panel Controls

Using the OSD Lock function

Using the On-Screen Display (OSD) Menu

Troubleshooting

Self-Test

Built-in Diagnostics

Common Problems

Product Specific Problems

Appendix

Safety Instructions

FCC Notices (U.S. only) and Other Regulatory Information

Contacting Dell

Setting Up Your Monitor

Maintenance Guidelines