Dell U3821DW Monitor Usage and Troubleshooting Guide
Summary: Learn how to use and troubleshoot issues related to the U3821DW Monitor.
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Instructions
For help with video or display issues such as: no video or no display, blank or black screen, flickering, resolution or color issues, horizontal or vertical lines, etc. refer to an expanding section below.
The key features of Dell U3821DW monitor are:
- 3840 x 1600 (21:9) resolution, plus full-screen support for lower resolutions.
- 95.29 cm (37.52 in.) wide viewable area (measured diagonally).
- Digital connectivity with DisplayPort, USB Type-C, and HDMI.
- Single USB Type-C to supply power (90 W) to a compatible laptop PC, while receiving video and data signals.
- Uses an Active Matrix - TFT LCD.
- The built-in KVM switch allows you to control up to 2 computers from a keyboard and mouse connected to the monitor.
- Ultrathin bezel minimizes the bezel gap in multimonitor usage, enabling easier setup with an elegant viewing experience.
- Supports Picture By Picture (PBP) and Picture in Picture (PIP).
- Plug and Play compatibility (if supported by your system.).
- Built-In Speakers.
- Supports Auto KVM for multiple input setup.
- Tilt, swivel, height, and rotating adjustment.
- Less than, or equal to 0.3 W standby power when in the standby mode.
- Optimize eye comfort with a flicker-free screen.
- Security lock slot.
Warning: The possible long-term effects of blue light emission from the monitor may damage your eyes, including eye fatigue or digital eye strain. ComfortView feature is designed to reduce the amount of blue light that is emitted from the monitor to optimize eye comfort.
Warning: Do not mount this monitor in vertical orientation due to the risk of damaging the monitor.
This section provides some specifications of the Dell U3821DW monitor. To learn more about the specifications of Dell U3821DW monitor, refer to the User's Guide at the Dell Manuals website.
| Panel technology |
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|---|---|
| Maximum resolution |
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| Viewing angle |
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| Contrast ratio |
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| Response time |
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| Curvature |
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| Color gamut |
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| Color depth |
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| Ports and connectors |
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| Built-In Speakers |
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Note: SuperSpeed USB 3.2 Gen1 Type-A 5 Gbps functionality requires a SuperSpeed capable computer.
Note: The USB ports do not work when the monitor is switched off. They only work when the monitor is powered on, or it is in standby mode.
Ensuring that your Dell monitor is set up properly. Assembling the monitor stand and setting up the monitor ergonomically. Connecting the cables and organizing them. These will only help make the viewing experience the best it possibly can be.
Attaching the stand
The standard monitor stand is detached when the monitor is shipped from the factory. To learn more about attaching the standard monitor stand. Refer to the Setting Up the Monitor section in the User's Guide of your Dell U3821DW monitor.
To learn how to set up any other stand with a monitor, refer to the respective stand setup guide for setup instructions.
Caution: Do not remove the monitor from the packaging box before attaching the stand.
Note: The Dell U3821DW monitor is 8.8 Kg (19.4 lb) without a stand fitted; handle with extreme care. It is recommended to have two people to lift or move this monitor.
Ergonomics
Where you put your monitor is almost as important as what model you buy. The monitor should be directly in front of you, at an arm’s length away (between 20-40 inches from your eyes). The top edge of the screen at eye level when you are sitting comfortably. You may need to adjust your chair height or the height of the monitor to achieve this.
Connecting your monitor to the PC
To connect your Dell U3821DW monitor to your PC:
- Turn off your PC and disconnect the power cable.
- Connect the DisplayPort, HDMI, or USB Type-C cable to the corresponding video or display port on the back of your PC.
(Select one, do not connect all three to the one monitor and PC.)
Note: Dell U3821DW supports display over USB Type-C port with Alternate mode DP 1.4. Ensure that the USB Type-C on your PC supports Alternate mode DP 1.2 or above. How to Connect a Monitor to a Dell Computer.
- Connect the USB upstream cable to the monitor and PC.
Dell U3821DW monitor orientation must always be in landscape mode. The Dell U3821DW has a curved monitor screen. This includes any wall-mounted monitors and monitors on a stand. In a multiple monitor setup, Dell U3821DW should not be rotated either to 180° (landscape) or 90° (portrait).
Caution: Dell U3821DW setup must comply to the recommended panel orientation and working angle only. Setting up the monitor in an orientation that is not recommended may damage the monitor and/or cause a safety hazard.
When setting up your Dell U3821DW monitor, ensure that the monitor power LED indicator is on the bottom right.
Using the Tilt, Swivel, and Vertical Extension
Note: This is applicable for a monitor with a stand. When any other stand is bought, please refer to the respective stand setup guide for set-up instructions.
With the stand attached to the monitor, you can tilt and swivel the monitor for the most comfortable viewing angle.
Figure 5.1: Using Tilt and Swivel on Dell U3821DW monitor
Figure 5.2: Dell U3821DW monitor stand height
Figure 5.3: Using slant angles on a Dell U3821DW monitor
When mounted on the wall or on a monitor arm, the set-up must comply to the recommended panel orientation and working angle.
Figure 6: Using Tilt and Swivel on Dell U3821DW monitor on an arm
Warning: The monitor should not be rotated 180° (landscape). The monitor should not be orientated at 90° (portrait).
Use the buttons at the rear of the monitor to access the On-Screen Display (OSD) menu of the monitor. To access the On-Screen Display (OSD) menu, press Button 5 (Figure 1) at the rear of the monitor.
Learn more about using the On-Screen Display (OSD) menu. Refer to the Operating Your Monitor section in the User's Guide of Dell U3821DW monitor.
Note: Any changes that you make are automatically saved. Whenever you move to another menu item, exit the OSD menu, or wait for the OSD menu to automatically close.
Figure 1: Dell U3821DW Power button and OSD Joystick
| Button | Function | Description |
|---|---|---|
| Button 1 | Power On/Off button (with LED indicator on front of the monitor). | Solid white light indicates that the monitor is On and fully functional. Blinking white light indicates the power save mode. |
| Joystick Control | Controls to make adjustments to the On-Screen Display. |
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Resetting a monitor to factory defaults can help resolve many video or display issues. To reset your Dell U3821DW monitor to factory default settings, follow these instructions:
- Press on the joystick on the monitor to enter the On-Screen Display (OSD) Menu.
- Press up or down on the joystick to highlight Others option in the menu and press on the joystick to select.
- Press up or down to highlight Factory Reset option in the menu and press on the joystick to select.
- Press on the joystick to confirm the reset action.
Figure 7: Dell U3821DW reset screen
If your Dell monitor has a blank or black screen, fuzzy or blurry image, flickering, distorted or any other screen abnormalities, running a diagnostic test will help determine if the Dell monitor is functioning normally. To learn more about diagnostic options on a Dell monitor, refer to the Dell knowledge-base article: How do I run diagnostics on a Dell monitor?
It is always essential to isolate the monitor while troubleshooting your computer for the following scenarios:
- No Power - Your computer is not powering ON or showing any signs of power.
- No POST - Your computer is not showing any indication of activity, the screen might be blank and will not display the Dell logo during start-up.
- No Video - You are unable to see any display on the screen, able to hear the windows chime but no display is seen.
Your Dell U3821DW Monitor provides a self-test feature check that allows you to check whether the monitor is functioning properly. If the monitor and computer are properly connected but the monitor screen remains dark, run the monitor self-test by performing the following steps:
- Turn off both your computer and the monitor.
- Unplug the video cable from the back of the computer. To ensure proper Self-Test operation, remove the video cables (HDMI, DisplayPort, or USB Type-C) from the back of the computer.
- Turn on the monitor.
If the monitor doesn't sense a video signal and is working correctly, it should report a message advising no video cable detected:
Figure 2: Dell U3821DW no video cable detected
- Turn off 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 card (GPU) and computer, because your monitor is functioning properly.
Your Dell U3821DW monitor has a built-in diagnostic tool. It helps to determine if the screen abnormality you are experiencing is a problem with the monitor or with the video card on your computer.
When you notice screen abnormalities like distortion, clarity, horizontal or vertical lines, color fade, it is always a good practice to isolate the monitor by running the Built-In Diagnostics.
- Make sure that the screen is clean (no dust particles on the surface of the screen).
- On the back of the monitor, press on the joystick and move it up/down/left/right for 4 seconds. A pop-up menu appears.
- Move the joystick to highlight the diagnostic icon (A monitor on top of a wrench) and press the joystick to confirm.
- A gray test pattern appears, carefully inspect the screen for abnormalities.
- Press on the joystick again. The pattern changes and the color of the screen changes to red.
- Inspect the display for any abnormalities.
- Repeat step 5 and step 6 to inspect the display in green, blue, black, white, and text screens.
- The test is complete when the white screen appears.
- Press on the joystick to exit the Built-In Self-Test diagnostics.
Note: If you do not detect any screen abnormalities upon using the built-in diagnostic tool, the monitor is functioning properly. Check the video card (GPU) and the computer.
If you notice any abnormalities during Built-In Diagnostics, you may get the monitor repaired or replaced if it is under warranty by contacting Dell Technical Support.
If you notice any abnormalities during Built-In Diagnostics, you may get the monitor repaired or replaced if it is under warranty by contacting Dell Technical Support.
During the LCD Monitor manufacturing process, it is not uncommon for one or more pixels to become fixed in an unchanging state. Which is hard to see and do not affect the display quality or usability. For more information, refer to the Dell knowledge-base article Dell LCD Monitor Pixel Guidelines.
This section provides information about troubleshooting steps that can help resolve the most common issues with the Dell U3821DW monitor. Alternatively, to learn more about troubleshooting common issues on Dell monitors, refer to the Dell knowledge-base article Troubleshooting Display or Video Issues on a Dell Monitor.
| Common Problem | What User Experiences | Possible Solution |
|---|---|---|
| No Video - Power LED Off | No picture |
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| No Video - Power LED On | No picture or no brightness. |
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| Poor Focus | Picture is fuzzy, blurry, or ghosting. |
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| Shaky or Jittery Video | Wavy picture or fine movement. |
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| Missing Pixels | LCD screen has spots. |
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| Stuck-On/Off Pixels | LCD screen has bright spot. |
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| Brightness Problems | Picture too dim or too bright. |
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| Geometric Distortion | Screen not centered correctly. |
When using DisplayPort input, the positioning adjustments are not available.
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| Horizontal or Vertical Lines | Screen has one or more lines. |
When using DisplayPort input, the positioning adjustments are not available.
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| Synchronization Problems | Screen is scrambled or appears torn. |
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| Safety-Related Issues | Visible signs of smoke or sparks. |
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| Intermittent Problems | Monitor malfunctions on and off. |
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| Missing Color | Picture does not have color. |
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| Wrong Color | Picture color is not good. |
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| Image Retention from a Static Image Left on the Monitor for a Long Period | Faint shadow from the static image appears on the screen. |
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| Picture Quality (Refresh rate of native resolution changes from 60 Hz to 30 Hz or the the color depth drops to 18 bits) | Incorrect refresh rate of missing colors issues. | Set USB Type-C Prioritization to High Resolution. |
| Screen image is too small. | Image is centered on screen, but does not fill entire viewing area. |
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| Cannot adjust the monitor with the joystick. | OSD does not appear on the screen. |
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| No Input Signal when user controls are pressed. | No picture, the power LED light is white. |
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| The picture does not fill the entire screen. | The picture cannot fill the height or width of the screen. |
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| No Network Connectivity. | Network dropped or intermittent. | Check that the USB Type-C Prioritization is set to high data speed. (Do not turn off the monitor during network connection.) |
| No video at HDMI/DisplayPort/USB Type-C port | When connected to some dongle/docking device at the port, there is no video when unplugging/plugging the cable from the notebook | Unplug the HDMI/DisplayPort/USB Type-C cable from dongle/docking device, then plug the docking HDMI/DisplayPort/USB Type-C cable to the notebook. |
| No sound coming from the external speakers. | Cannot hear and sound. |
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| Troubleshooting USB Issues | ||
|---|---|---|
| Specific Symptoms | What User Experiences | Possible Solution |
| USB interface is not working. | USB peripherals are not working. |
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| SuperSpeed USB 3.2 Gen1 interface is slow. | SuperSpeed USB 3.2 peripherals working slowly or not working at all |
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| Wireless USB peripherals stop working when a USB 3.2 device is plugged in. | Wireless USB peripherals responding slowly or only working as the distance between itself and its receiver decreases. |
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| USB Type-C port does not supply power. | USB peripherals cannot be charged. |
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To learn more about how to view or download the User Guides and Manuals for your Dell product. Refer to the Dell knowledge-base article Manuals and Documentation for your Dell Product.
- Dell U3821DW – User’s Guide
- Dell U3821DW – Quick Setup Guide
- Dell U3821DW – Dell Display Manager User’s Guide
Frequently asked questions
Using Windows Display Settings
In Windows 8 or 8.1 and Windows 7:
- For Windows 8 and Windows 8.1 only, select the Desktop tile to switch to classic desktop view.
- Right-click on the desktop and click Screen Resolution.
- Click the dropdown list of the Screen Resolution and select 3840 x 1600.
- Click OK.
In Windows 10:
- Right-click on the desktop and click Display Settings.
- Click Advanced display settings.
- Click the dropdown list of the Resolution and select 3840 x 1600.
- Click Apply.
Using Nvidia Control Panel
To change the resolution using the Nvidia Control Panel:
- Right-click on the desktop and click Nvidia Control Panel.
- Click the + symbol next to Display on the left pane.
- Select Change Resolution under Display.
- In the dropdown menu on the right pane, select the resolution 3840 x 1600.
- Click Apply.
Using AMD Catalyst Control Center
To change the resolution using the AMD Catalyst Control Center:
- Right-click on the desktop and click AMD Catalyst Control Center.
- Click the + symbol next to Display on the left pane.
- Select Change Resolution under Display.
- In the dropdown menu on the right pane, select the resolution 3840 x 1600.
- Click Apply.
Note: If you do not see the recommended resolution as an option. You may need to update the video card (GPU) driver by visiting the Dell Drivers & Downloads website or the video card (GPU) manufacturers website. To learn how to download and update a device driver, refer to the Dell knowledge-base article: How do I download and install a device driver?
To reset the Dell U3821DW Monitor to factory defaults, refer to the Reset to Factory Settings section of this article.
The Dell U3821DW monitor has two built-in diagnostics that are available:
- Self-Test Feature Check - The self-test feature check on the Dell U3821DW monitor allows you to check whether the monitor is functioning properly.
- Built-In Self-Test - The Dell U3821DW monitor has a built-in self-test that helps you identify if the screen abnormality is with the monitor or the video card (GPU) on your computer. When you notice screen abnormalities like distortion, clarity, horizontal or vertical lines, color fade. It is always a good practice to isolate the monitor by running the Built-In Diagnostics.
To learn how to run a diagnostic test, refer to the Running Diagnostics on Dell U3821DW Monitor section of this Dell knowledge-base article.
The Troubleshooting section of this Dell knowledge-base article provides information about troubleshooting common issues with the Dell U3821DW monitor. The section has troubleshooting steps on how to resolve power issues, video issues, color or clarity issues, distortion issues, horizontal or vertical lines, brightness issues or pixel issues and so on.
To navigate the On-Screen Display (OSD) menu, use the joystick on the monitor. The monitor control buttons are usually on the right side, either on the side, front, or bottom of the monitor, but in this case they are on the rear. To access the On-Screen Display (OSD) menu, press on the joystick on the rear of the monitor.
For more information about using the On-Screen Display (OSD) menu and different menu options. Refer to the Operating Your Monitor section in the User's Guide of your Dell U3821DW monitor.
.Additional monitor information like the model number, firmware version and Service Tag can be accessed from the monitor's OSD (On-Screen Display).
- Press on the joystick (Figure 1) on the monitor to enter the On-Screen Display (OSD) Menu.
- Press up or down to highlight Others option in the menu and press on the joystick to select.
- Press up or down to highlight Model Number or Firmware Version option in the menu and press on the joystick to select.
- Press on the joystick to exit the OSD menu.
Dell U3821DW supports both DisplayPort 1.4 connectivity with your PC. If the video or graphics card (GPU) on your PC supports DisplayPort 1.2, it is required to change the monitor to DisplayPort 1.2 mode.
Note: The default factory setting on the Dell U3821DW is DisplayPort 1.4 (DP1.4).
- Press on the joystick (Figure 1) on the monitor to enter the On-Screen Display (OSD) Menu
- Press up or down to highlight Input Source in the menu and press on the joystick to select.
- Press up or down to highlight DP in the menu.
- Press and hold on the joystick for approximately 10 seconds until the DisplayPort configuration message appears.
Figure 1: Dell U3821DW Power Button and OSD Joystick
- Press on the joystick to select Disable and change the display mode to DisplayPort version 1.2
Dell U3821DW supports both HDMI 2.0 and HDMI 1.4 connectivity with your PC. If the video or graphics card (GPU) on your PC supports HDMI 1.4, it is required to change the monitor to HDMI 1.4 mode.
Note: The default factory setting on the Dell U3821DW is HDMI 2.0.
- Press on the joystick (Figure 1) on the monitor to enter the On-Screen Display (OSD) Menu
- Press up or down to highlight Input Source in the menu and press on the jostick to select.
- Press up or down to highlight HDMI in the menu.
- Press and hold on the joystick for approximately 10 seconds until the HDMI configuration message appears.
Figure 1: Dell U3821DW Power Button and OSD Joystick
- Press on the joystick to select Disable and change the display mode to HDMI version 1.4
USB Type-C port on your Dell U3821DW supports USB Power Delivery, Data, and DisplayPort video signal. The USB Type-C port can be used for video and data signal, and supply power (90 W) to a compatible laptop PC using a single USB Type-C cable that is provided with the monitor.
Note: Dell U3821DW can supply power via the USB Type-C cable only to a compatible laptop PC that supports Power Delivery (PD) over USB Type-C. Not all laptop PCs with USB Type-C support Power Delivery, for more information refer to the User Manual or contact your laptop manufacturer.
Note: USB Type-C power delivery-compliant port (PD version 2.0) delivers up to 90 W of power. If your laptop PC requires more than 90 W to operate and the battery is drained. It is recommended you use the standard AC adapter of the laptop PC to power on and charge the laptop battery.
If you are using a Dell laptop PC that supports charging via USB Type-C. It is recommended to update the BIOS and Video or Graphics card (GPU) driver. To learn how to download and update a device driver, refer to the Dell knowledge-base article: How do I download and install a device driver?
Dell U3821DW monitor orientation must always be in landscape mode. This includes any wall-mounted monitors and monitors on a stand. In a multiple monitor setup, Dell U3821DW should not be rotated either to 180° (landscape) or 90° (portrait).
Caution: Dell U3821DW setup must comply to the recommended panel orientation and working angle only. Setting up the monitor in an orientation that is not recommended may cause.
When setting up your Dell U3821DW monitor, ensure that the monitor front panel buttons is on the bottom right.
Using the Tilt, Swivel, and Vertical Extension
Note: This is applicable for a monitor with a stand. When any other stand is bought, please refer to the respective stand setup guide for set-up instructions.With the stand attached to the monitor, you can tilt and swivel the monitor for the most comfortable viewing angle.
Figure 5.1: Using Tilt and Swivel on Dell U3821DW monitor
Figure 5.2: Dell U3821DW monitor stand height
Figure 5.3: Using slant angles on the Dell U3821DW monitor
When mounted on the wall or on a monitor arm, the set-up must comply to the recommended panel orientation and working angle.
Figure 6: Using Tilt and Swivel on Dell U3821DW monitor on an arm
Warning: The monitor should not be rotated 180° (landscape). The monitor should not be orientated at 90° (portrait).
Affected Products
Dell U3821DWArticle Properties
Article Number: 000182604
Article Type: How To
Last Modified: 18 Jul 2025
Version: 5
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