Why My Portable Monitor Shows No Signal?

Have you been slapped with a "No Signal" screen on plugging in your portable monitor to your laptop? It doesn't necessarily mean you bought a faulty monitor. Maybe it just entered power-saving mode? Let's make it clear; don't confuse "no response" with a "No Signal" problem.

Portable monitors are excellent as they make it easier to multitask when you have a lot to do with limited time. Besides, they let you carry them anywhere so you can continue with your work. If you recently encountered a challenge connecting your monitor to a device, understanding how it works can help you troubleshoot the problem faster.

How Do Portable Monitors Transmit Video Signals?

The main cause of a "No Signal" notification on your display indicates that your monitor isn't communicating with your video source device. The device can be a laptop, gaming console, or smartphone.

Although not necessary, understanding how data is transmitted from your device to your portable monitor can play a significant role in helping you identify and fix the problem. If there is an issue with cables or adapters, replacing them with new products can quickly resolve the problem.

Types of Data Connectivity Ports on Portable Monitors

A portable monitor transmits data through ports that connect to a notebook, smartphone, or device to output video signals.

Today's portable monitors come with various ports, each serving a different function. With the right monitor, you can enjoy an incredibly smooth media streaming experience, whether watching videos or playing games. Most modern portable monitors transmit video and audio signals through DisplayPort, HDMI, or USB-C.

Choosing the correct port type will mostly depend on your needs and is a big game-changer when you want to experience a smooth, seamless viewing experience.

USB-C

USB Type C, often named USB-C or Type-C, is one of the best things that ever happened to the world of data transmission. This is because it supports simultaneous high-speed data transfer and power delivery while meeting USB 3.0, DisplayPort 1.4, and PD Power Delivery standards (also known as full-function/feature Type-C). Most modern portable monitors will have at least two USB-C ports in place of DisplayPort and HDMI. Sometimes, two USB ports serve different purposes: one is used for power, and the other is for connecting to a laptop or other devices.

USB-C is known for its great versatility as it is reversible; you can plug it in any direction and still work. Besides, it supports the USB Power Delivery (PD) protocol, which can provide up to 100 watts of power. Due to these great advantages, USB-C ports make it easier to use portable monitors with your laptop, tablet, smartphone, and gaming console. USB Type-C supports several different versions and protocols. The higher the version, the better it can handle signal transmission. The table below explains the different USB-C versions and what they offer:

Protocol	Fastest data transfer speed	Description	Example Uses
USB 2.0	480 Mbps	Basic data transfer and power delivery.	Standard charging cables, basic peripherals.
USB 3.0 / USB 3.1 Gen 1/USB 3.2 Gen 1	5 Gbps	Faster data transfer and power delivery.	External hard drives, high-speed data cables.
USB 3.1 / USB 3.1 Gen 2 / USB 3.2 Gen 2	10 Gbps	Higher data transfer speeds and power delivery.	High-performance SSDs, faster data cables.
USB 3.2 / USB 3.2 Gen 2x2	20 Gbps	Ultra-high data transfer speeds.	High-performance peripherals, ultra-fast storage.
USB4	40 Gbps	Data transfer, Thunderbolt 3 compatibility, enhanced power delivery.	Modern laptops, high-resolution monitors.
Thunderbolt 3	40 Gbps	Data transfer, video output, power delivery, device daisy-chaining.	External GPUs, high-speed storage, multi-display setups.
Thunderbolt 4	40 Gbps	Enhanced performance requirements, backward compatibility.	Premium laptops, advanced docking stations, high-performance peripherals.
DisplayPort over USB-C	40 Gbps	Video output via USB-C.	Connecting to external monitors and projectors.
HDMI over USB-C	40 Gbps	HDMI video output via USB-C adapters.	Connecting to TVs and HDMI monitors.
Power Delivery (PD)	100W	Higher power delivery for charging and powering devices.	Charging laptops, powering USB-C devices.

HDMI Port

HDMI (high-definition multimedia interface) has established itself as the standard in home entertainment, and it's found in every major brand of TV, Blu-Ray player, video game system, and home theater.

It allows you to transmit uncompressed video, audio, and even data over a single cable. It's the standard for HD quality streaming and has been adopted by most prominent companies in the media industry.

There are three different HDMI shapes: the HDMI standard port, the Mini HDMI port, and the micro HDMI port. The HDMI standard port is often found in industrial monitors.

Mini HDMI is designed to be slim and is commonly found as a standard interface on portable displays. The micro HDMI port is still quite rare in portable displays, with its primary use being in the Raspberry Pi 4.

You may have noticed that there are different versions of HDMI cables: HDMI 1, 1.1, 1.2, 1.4, and 2.1. However, what do these numbers mean? From the prior version 1 in 2004 to the current version 2.1, the HDMI has gone through a few versions. The more advanced the version, the higher the HDMI compatibility. For example, to support 4 K resolution, firmware version 1.4 was released. Therefore, HDMI 1.4 stands for Vertical refresh rate of 60Hz and 120Hz@1080P and 2K (1440p), it does not support 120Hz@2K and has 30Hz@4K.

HDMI 2.0 is backward compatible with HDMI 1.4 and supports a 60Hz and 120Hz refresh rate at 2K (1440p) resolution, and up to 4K (2160p) resolution at a 60Hz refresh rate, but does not support a 120Hz@4K.

HDMI 2.1, while it is backward compatible with HDMI 2.0, supports 4K@60Hz and 120Hz when scaling up to a maximum of 8K@30Hz.

While HDMI has undergone several updates, not all versions use the same type of cable. There are three categories of HDMI cable: Standard, High-Speed, and Ultra-High-Speed. HDMI Standard and HDMI High-Speed can also be further divided into Standard with Ethernet and High-Speed with Ethernet. HDMI cables offer different functionalities based on signal transmission speed (bandwidth) and the HDMI version associated with the cable.

HDMI Type	HDMI Versions	Support and Features
HDMI Standard	HDMI 1.0 to 1.2a	Supports most home devices and up to 1080p or 720p resolution
HDMI High Speed	HDMI 1.3 to 2.0	Supports higher resolutions and bandwidths, up to 4K (30Hz) and 3D video
HDMI Standard with Ethernet	HDMI 1.4 and above	Similar to HDMI Standard but adds an Ethernet channel for network connectivity
HDMI High Speed with Ethernet	HDMI 1.4 to 2.0	Similar to HDMI High Speed but adds an Ethernet channel for network connectivity
HDMI Ultra High Speed	HDMI 2.1	Supports up to 8K (30Hz)

If your HDMI cable isn't compatible, consider getting a new Mini HDMI to HDMI cable that supports 60Hz and 4K@2160p. This should help you connect your device to the monitor successfully.

DisplayPort

Like HDMI, DisplayPort cannot support power transmission to a portable display, hence used purposely for video signal transmission. DisplayPort connectors come in two different styles: the standard DisplayPort (DP) and the smaller Mini DisplayPort (Mini DP). The DP is a rectangular connector, about 16.8 mm x 4.7 mm, with rounded corners and a locking button to keep it secure. The Mini DP is shorter, thicker, and has no locking feature. Both connectors have 20 pins, and the Mini version might also show a Thunderbolt icon. Additionally, portable monitors designed with DP or Mini DP ports are not common. However, some industrial monitors might use Mini DP, typically with DisplayPort 1.4 versions.

DisplayPort comes in four versions: 1.2, 1.4, 2.0, and 2.1. Each version offers different speeds and features.

Version	Max Resolution	Max Data Rate	Key Features
1.2	3840 x 2160 (4K) @ 60Hz	17.28 Gbps	Supports HDCP 2.2 protection, Multi-Stream Transport (MST), 3D display
1.4	5120 x 2800 (5K) @ 60Hz, or 7680 x 4320 (8K) @ 30Hz	25.92 Gbps	Supports HDR10, Display Stream Compression (DSC) lossless compression
2.0	7680 x 4320 (8K) @ 60Hz, or 10240 x 4320 (10K) @ 60Hz	77.4 Gbps	Supports HDR10+, Dolby Vision, VESA DisplayHDR standard, USB Type-C Alt Mode
2.1	7680 x 4320 (8K) @ 60Hz, or 10240 x 4320 (10K) @ 60Hz	77.4 Gbps	Supports HDR10+, Dolby Vision, VESA Display HDR standard, USB Type-C Alt Mode, Improved bandwidth management

VGA and DVI

VGA (Video Graphics Array) is an older display standard introduced by IBM in 1987 that uses analog signals. The VGA connector has 15 pins arranged in three rows of five. And the DVI (Digital Visual Interface) connector standard was introduced by the Digital Display Working Group (DDWG) in 1999. It features a 24-pin connector and was designed for traditional digital display devices such as LCD monitors. You may find VGA and DVI on some industrial monitors.

Now that we've familiarized ourselves with how portable monitors receive data from input devices, let's jump to how to connect your portable monitor to your laptop, gaming console, or smartphone.

How to Connect Your Portable Monitor to a Laptop

Sometimes the "No Signal" issue could be due to an improper connection of an external monitor to your device. You can check which port your laptop uses to connect to the portable monitor. This might help you figure out if the no-signal issue is due to the port.

USB-C to USB-C Connection

If you want a trouble-free way of connecting your portable monitor to a video output device, USB-C to USB-C connection is the best. This connection requires only a single cable to transmit video signals and power simultaneously.

USB-C to USB-C connection is ideal for connecting your laptop, android, or Apple device to your second monitor. Make sure your notebook has a Full Feature USB Type-C 3.0, USB 4, Thunderbolt 3, or Thunderbolt 4 port, or a higher version. The following Apple MacBook models which support Thunderbolt 3, Thunderbolt 4, or USB4 can connect the portable monitor directly: MacBook Pro 13-15 inch (2016-2023), MacBook Air (2018-2022), and MacBook 12 inch (2015-2017). If you are using a laptop from another brand and are unsure whether your USB-C port supports full-function USB Type-C 3.0, you can check if it supports USB 3.0, DisplayPort 1.4, and PD Power Delivery.

If your computer doesn't have any of the ports mentioned above, your portable monitor won't work properly and will show 'no signal.' In this situation, to get your monitor working, you can use a HDMI to Mini HDMI connection. Alternatively, you can use a USB-A to HDMI adapter and install the DisplayLink driver to connect to your portable monitor. You can turn to your device provider for help or check the device information on the official website to confirm the related protocols of its USB-C if you don't know.

Most current portable monitors often include the USB-C to USB-C cable. Connect it to the correct Type-C port on the monitor because sometimes there is a Type-C port for power only, marked as a PD port.

If you've made your connections properly (your laptop supports the Thunderbolt 3.0 protocol or higher), your portable monitor power indicator lights green, and the "No Display" notification persists, you should proceed to troubleshoot.

Connecting with Mini HDMI, HDMI, or DisplayPort

If your laptop has no Thunderbolt or USB-C port, you can transmit video signals using a Mini HDMI, HDMI or a mini DisplayPort, depending on what ports the second portable screen has. For instance, by using a HDMI to Mini HDMI adapter, you can connect your laptop’s HDMI port to your portable monitor’s Mini HDMI port to transmit the signal. Remember to power it using a wall socket outlet if your portable display does not have an in-built battery.

Additionally, some people might think they can use a standard DisplayPort to connect a portable monitor, but that's not the case. There are two main types of DisplayPort: the standard DisplayPort (DP), which is commonly found on the dedicated graphics card for a desktop computer, and Mini DisplayPort (Mini DP), a smaller version of DisplayPort. Mini DP was widely used in some laptops from the 2010s, especially in Apple MacBooks and Microsoft Surface devices.

How to Connect Your Portable Monitor to Your Gaming Console

Gaming consoles typically connect to portable monitors with HDMI and USB-C The table below shows the ports and protocols used by most gaming consoles.

Interface	Protocol	Common Devices
HDMI	HDMI 1.4, HDMI 2.0, HDMI 2.1	PlayStation 4/5, Xbox One/Series X/S, Nintendo Switch (via dock) Steam deck ROG Ally
USB-C	USB-C 2.0/ 3.2 Gen 2 (via DisplayPort Alt Mode)	Nintendo Switch Steam deck ROG Ally

 

In handheld mode, the Switch does not use HDMI output or connect to external displays. If users want to connect the Switch to an external display, they must place the device in its dedicated dock, which connects to the display via an HDMI interface. However, some Nintendo Switch models have advanced USB-C ports that allow for a direct connection to portable displays.

How to Connect Your Portable Monitor to a Smartphone?

Not all smartphones can connect to portable monitors. To ensure compatibility, check the table below. If your phone supports the listed ports and protocols, it should connect and display properly. Otherwise, you might just end up charging your phone instead of using the monitor. We also have a list of smartphones with DisplayPort Alt Mode for models released before 2022. For the latest models that support DisplayPort Alt Mode, please reach out to the vendor for more information.

Keep in mind that phones with USB Type-C ports need to support Alternate Modes to connect to a portable display using the right adapter. Phones with Micro-USB ports need to support either MHL (Mobile High-Definition Link) or SlimPort protocols to connect to a portable display using an adapter. We've summarized the common types of phone ports and how to connect them to a portable display, hoping it will be helpful to you.

Interface Type	Technical Support	Adapter Type	Compatible Portable Display Interfaces
USB Type-C	Alternate Modes	USB-C to HDMI Adapter	HDMI
		USB-C to DisplayPort Adapter	DisplayPort
		USB-C to VGA Adapter	VGA
		USB-C to Mini DisplayPort Adapter	Mini DisplayPort
		USB-C Hub	HDMI, USB-A, USB-C, VGA, etc.
Micro-USB	MHL, SlimPort	Micro-USB to HDMI Adapter	HDMI
	SlimPort	Micro-USB to VGA Adapter	VGA
Lightning	Apple Lightning	Lightning to HDMI Adapter	HDMI
		Lightning to DisplayPort Adapter	DisplayPort
		Lightning to VGA Adapter	VGA
		Lightning to USB-C	USB-C

The Most Obvious Reasons for Portable Monitors Not to Work

As highlighted, the causes of a monitor not working as required could be due to no response or a second monitor not detected.

No response from your portable monitor means that the display is black as if it is not plugged into your laptop (when using a single cable) or does not have a power source. In such a case, the power indicator LED is usually off. The straightforward solution is to ensure that it's plugged into your device (when using a single cable) or a wall socket outlet.

The Portable Monitor Not Receiving Power

Before we jump into the deep troubleshooting bit, the problem of a portable monitor having no response could be a matter of power input. Checking whether your monitor is receiving power should be your first action. Thankfully, it's pretty simple to check when dealing with portable screens.

For a monitor that uses the USB-C for power, ensure it's connected to the wall charger and the power indicator lights green to show that it is receiving power. If not, it will have no lights on. For a battery-powered monitor, ensure the battery is fully charged before connecting.

"No Signal" Message on Display with Green Power Indicator Light

If your portable monitor is plugged in and shows the "No signal" message, you should check whether the device is connected to a "signal source," which means that you should use cables or accessories to connect your phone, tablet, or computer to the display. However, if the signal source is connected and the device still shows no signal, you should proceed to fix the issue. There are several reasons why this could happen. If you're a hands-on guy and don't mind troubleshooting what might be the problem, this guide will explain a few of the possible causes of a lack of signal and how to resolve them.

The Portable Monitor Enters Power-Saving Mode

When a portable monitor enters power-saving mode, it often displays "No Signal." This typically occurs when the connected device goes to sleep or the monitor is not receiving any input.

Before this, make sure that your signal device is not in sleep or standby mode. To prevent a portable monitor from entering sleep mode, you can adjust the power settings through "Power Options" on Windows or "Energy Saver" on Mac. Don't forget to check the monitor's menu for sleep mode settings, use anti-sleep software like Caffeine, update your drivers, and disable any power management features on the monitor itself.

Troubleshooting The "No Signal" Problem on Portable Monitors

If you managed to pass the no-response problem, which is often caused by a lack of power input, your portable monitor may or may not be working. The "No Signal" message will be shown on the display if it is plugged into your device and is receiving power as expected.

The following are some of the main causes of a "No signal" response on a portable monitor and how to fix them.

Port Compatibility Issues

As we mentioned before, portable monitors connect to devices through USB Type C, HDMI, and other ports. If connecting to a laptop using USB-C with one cable, ensure that you have a Full Feature USB Type-C 3.0, USB4, Thunderbolt 3, Thunderbolt 4, or above later. If not, try using another connection option like HDMI.

If you're using a smartphone to connect to your portable monitor, ensure it has a USB-C 3.1 or later. USB 3.1 ports are upgraded USBs capable of transmitting both power and data. Most modern smartphones will have USB-C ports, but few of them have video output functions. Phone brands that have upgraded the Type-C port to full feature function are mostly found in the Samsung Galaxy series, Huawei Mate series, and OnePlus.

Many users are using the second external screen with computers and PCs. If the device is not yet upgraded to an HDMI port for video output, they need to convert VGA or DVI to HDMI. Keep in mind that you’ll need a VGA-to-HDMI converter with audio support. Otherwise, even if you get everything connected, you’ll end up with video but no sound. If that's the case, ensure your adapter can support VGA to HDMI compatibility because some adapters offer only one-way connectivity, HDMI to VGA.

You may also face the "No Signal" message when trying to connect your portable screen display to a Nintendo Switch console via a USB-C to USB-C cable. In such a case, ensure the monitor is powered via the Switch charger rather than the monitor's charger. If you want a more stable connection, you may use the HDMI port of the Switch dock to prevent poor contact from shaking or movement when moving the host.

Power Supply Insufficiency

When connecting a single USB-C cable, your portable monitor gets power from your device. Sometimes the power might not be sufficient to enable the monitor to function optimally.

Mainly, the power insufficiency is caused by your device limiting the USB-C power output. When the display is powered on, it requires a high power current and sometimes exceeds the device's supply, especially for a smartphone.

Another cause of low power supply can also be the higher power requirement. Laptop external monitors with high resolutions such as 4K or wider sizes like 22 inches will require more power input than what a device can give.

In these cases, you are suggested to go for a portable monitor with an internal battery or an external power input. However, if you cannot find a power socket, a power bank might also work.

If you want to use a power bank to charge your portable display, it's a good idea to choose one that supports the PD Protocol Type. Some lower-wattage power banks might only support PD 1.0 or PD 2.0, which may not provide enough power for your needs. The table below outlines the output power and corresponding protocols for different power banks. Picking one that has a power rating equal to or greater than the wattage of your monitor’s original charger. For instance, if your monitor’s charger is 65W, go for a power bank that’s 65W or higher to ensure it charges effectively.

(DP) Power Output	PD Protocol Type	Notes
5W - 10W	PD 1.0 / PD 2.0	Basic charging power and voltage.
10W - 18W	PD 2.0 / PD 3.0	Enhanced power delivery, supports higher power and fast charging.
18W - 30W	PD 2.0 / PD 3.0	Supports dynamic voltage adjustment and higher power transfer.
30W - 60W	PD 3.0	Higher power transfer includes a Programmable Power Supply (PPS).
60W and above	PD 3.0	Advanced features include higher power transfer and improved efficiency.

Wrong Display Settings

Computer monitors out-of-the-box may or may not have the appropriate settings to support plug-and-play. The most likely cause is that the auto-search functionality is not turned on, and the monitor may need to be directed to the source of the input signal.

Select your monitor's control panel and find the input signal source to set it right. Note that if you had used a USB-C connection during your last session and in your subsequent session you're using HDMI, you'd need to change the setting.

Thanks to the portable display technology, the Autosearch setting is build-in the monitor, and it will refresh and connect using your new connection medium. Should this bear no result, select the appropriate setting, either HDMI, MiniDisplay, or VGA, from the input source screen, and your monitor should light up.

Sometimes, the wrong settings could be on your laptop. For example, disabling external display output can also cause a no-signal issue. It is recommended to check the display settings on the main device to ensure that external display output is enabled and try detecting the monitor again. If you had previously connected to a second screen and did exit with the Show Desktop Only on 1 or 2, you will also get the "No signal" message. Check your laptop and change the display setting to Duplicate or Extend these Displays.

Obsolete Graphics Driver on Your Laptop

Some devices might not display anything if the refresh rate is below 30Hz. To fix this, make sure to set the output refresh rate to 30Hz or higher. If your laptop doesn't recognize a second monitor, the problem could be the graphic driver. Doing an update allows your computer to improve the display resolution as well as identify any secondary monitor plugged in.

Updating the graphic driver is simple enough if you're using a Windows OS. Microsoft often releases new updates from time to time, and your PC downloads them automatically and schedules a time to install them. If you haven't restarted your PC for some time and have a notification message that it has pending updates, a restart might do the magic.

Apart from a restart, you can also check for updates manually. To do this:

1. Go to Windows Settings-> Updates & Security.
2. Select the Windows Update option to check whether there are any pending updates.
3. If none is listed, click the Check for Update button.

Running Windows update check won't let you pick the updates to install. But the OS will choose the required updates and install them for you.

Manually Updating the Graphics Driver on Windows

If you recently did a Windows update, you may then require to update the graphics driver manually. Using the Device Manager utility, you can search the web for the graphics driver updates suitable for your laptop's graphic card. To do this:

· Simultaneously press the Windows Start Key and R to start the Windows Run box.

· type in devmgmt.MSC then presses the enter key to open Windows Device Manager.

· On the Device Manager window, scroll to the Display adapters and expand it to list the dedicated and integrated graphics drivers.

· Click to select a graphic driver, then right-click and select Update Driver.

· On the pop-up window, choose Search automatically for drivers. The OS will auto-search for the right graphic drivers, download, and install them.

Updating Graphics Driver on MacBook

Mac OS usually comes with its graphic display driver built-in. That means you cannot install the graphic driver update only, you'll need to update the whole operating system. To do this:

· Click the Apple logo to open the menu.

· Click the "Software Update" option.

· Mac OS will indicate if there are updates available that need to be installed. If a graphic driver update is available, it will be included as part of the OS update.

When your laptop's graphic driver is up to date and everything is in order, the portable monitor should be able to light up as expected.

Port and Cable Connectivity Issues

After trying out every suggestion given above to sort out the "No Signal" problem without avail, it's time to confirm if the connection ports and cables you're using are working fine.

Faulty Connection Ports and Cables

Whether a USB-C or HDMI port, they can develop problems that might render connectivity to a portable monitor impossible. To ascertain if that is the case, try using the laptop's ports with another device. If it's an HDMI port, try to connect to a TV HDMI port using an HDMI cable. If it works well, that cancels out the suspicion of a faulty HDMI.

Alternatively, you can try connecting the portable monitor to a different laptop to ascertain whether your laptop's ports are faulty. If it does work, then you know that there is an issue with that specific port. If it doesn't, you can try to connect your laptop to a different portable monitor, which will rule out all possible issues on both your laptop and portable monitor ports.

Faulty Connection Cables

Sometimes, the issue could be with your connection cables. After prolonged use, a cable may become loose when connecting to a USB port. You can try fumbling it while still connected to the port to see if your screen will light up.

If that doesn't work, the next thing is to try and test the cables. Test the USB-C and HDMI cables on different laptops and portable monitors. If all fail, you might want to replace them. Ensure that the cables are of high quality and suitable for the required data transfer. Check for any visible damage or wear. You can purchase a new 3-in-1 HDMI Screen Mirroring Cable . This product is plug-and-play, widely compatible, supports HD 1080P video and audio signals, and helps you project your screen smoothly. Alternatively, you may use an Android app known as USBCheck to determine if a USB-C cable is working or not.

Faulty Portable Monitor Ports

Another possibility is that your monitor's port may be broken or faulty. In that case, things may become very complex for you to fix. But first, you can test the ports using a different cable and a laptop. If it doesn't light up, then we may conclude that the ports are faulty.

For a portable second display under warranty, you can arrange for the supplier to fix or replace it, depending on the terms and conditions of the purchase.

Summary

Monitors Screens for Laptops are the easiest way to multitask to get many things done in a fraction of time. While these monitors are ideal for use both outdoors and indoors, it can sometimes be troublesome to get them to work with your device, especially if it's your first time using one.

For starters, most portable monitors can start right out of the box without doing any configurations as long as the connections are made right. If you can't get your second monitor to work, first check to ensure that the display is receiving power. This is applicable primarily if the monitor has no response or a black screen.

For the "No Signal" message, the second monitor is not detected, it is an indication that the portable monitor is powered but not receiving video signals from your device. The above troubleshooting tips should help you get it to work. In a situation where all efforts bear no positive result, you may opt to return it to the supplier if it's still under warranty. After returning the item, we recommend purchasing our portable monitor, as it is of high quality and offered at very competitive prices. Come and shop now!