Why is Samsung Dex Not Working? Try These Quick Fixes:

Why is Samsung Dex not working? So you have a Samsung Dex compatible phone and you can’t seem to get it to work. I was struggling with this problem for a while, and I’ll quickly share some possible solutions with you.

Samsung Dex is a really cool new feature developed by Samsung that actives when the device is plugged into a larger screen. The mode transforms the regular phone layout into a full-screen, desktop-like experience, very similar to Windows.

Quick disclaimer: If you are having a problem with Dex, it’s better to contact Samsung for official support. The tips in this article are simply what I have found to work, I can’t guarantee they’ll work for you. But it’s somewhere to start.

Why is Samsung Dex Not Working?

The reason Samsung Dex is not working could be because your phone is in battery-saving mode, the USB-C to HDMI adapter is faulty, your phone’s USB-C port is wet, the dongle doesn’t provide enough power, or your phone doesn’t have the latest Knox update.

Like most IT-related problems, it can be challenging to narrow down what’s preventing Samsung Dex from starting as it should.

The reason could be either your phone’s battery is too low or it’s in battery saving mode. The problem could also be with the adapter, phone model, phone software, charging port, cable, and more.

Continue reading to learn more about common Samsung Dex problems, and how to troubleshoot them. Before you know it, the mode should be up and running!

1 – Get a Better Dongle or Dex Station:

Dex stations are great because they’re an all-in-one station with a USB-C charger, two USB ports, and an HDMI cable.

Here’s a good option:

Super portable too, and you can use them with any USB-C cable or phone. Yeah, it’s a little more expensive than an adapter, but it’s much better quality and more reliable.

Better yet, they keep your phone upright, so you can use it to reply to messages and other stuff while using Dex on a bigger screen. Very cool.

2 – Try an Adapter with External Power

While Samsung Dex usually starts with any USB-C to HDMI adapter, in some cases, you might need one that has a charge port.

The extra charge port can not only improve the performance of the adapter but also charge your phone at the same time.

Here’s an adapter that could work:

I recommend getting a USB-C to HDMI adapter that has a charging port, so you can not only keep your phone charged but also have the right power for Samsung Dex.

Bear in mind, some phones just aren’t compatible with certain adapters. And some adapters are just garbage, so that’s something to think about. One more thing is, if you use a portable monitor, then you need to make sure the monitor has it’s own source of power.

I can confirm that my S8+ Samsung Dex can start with a regular USB-C to HDMI adapter, no extra power is needed.

Most of the time, Dex won’t launch because the adapter has issues, here are a few:

1. 4-in-1 USB-C Hub to HDMI with 2 USB Ports 
2. 5-in-1 USB-C Hub to HDMI with 2 USB Ports and SD Card 
3. USB-C to HDMI Adapter Only (Cheaper)

I recommend buying a USB-C to HDMI adapter that has at least one extra USB port for a keyboard & mouse.

With the extra USB port, you can connect your current input devices. Alternatively, you could consider looking for a Bluetooth keyboard and mouse.

3 – Your Phone’s USB-C Port is Dirty or Damaged

Samsung Dex requires a stable connection to work, and Samsung Dex could not be working because of a faulty USB-C (charging port) on your phone.

If your phone struggles to charge, especially fast-charge, with multiple USB chargers, chances are something is wrong with the port. It could be something easy to fix, such as; water got into it (leave it to dry for a few hours) or some dirt got inside (clean it with a toothpick) or it could be permanently damaged.

I would clean the charging port with some toothpicks and try again. If it’s water, don’t worry, most Dex compatible phones are waterproof, and the phone should detect moisture in the port and prompt a warning telling you not to charge the phone until the port is dry.

If there’s water inside, you won’t be able to use Dex because Dex transfers a lot of power through the cable. You can shake it, wait it out, or leave the phone’s port pointed toward a normal fan.

Warning: Never use a hairdryer to dry a wet phone’s port because the heat could damage the internal components. Use a normal fan to speed up the process.

4 – Check for Compatibility & Software Issues:

To start, you’ll want to make sure that your phone is compatible with Samsung Dex. It’s a relatively new feature, so not all phones are compatible.

If you do not have a Samsung Dex supported phone, then you won’t be able to use the mode. Remember, at the moment, Samsung Dex is only available on Samsung devices.

This mode works best with Galaxy S10 and New Phones. 

The Samsung DeX service is currently available on the mobile devices listed below:

▷ Smartphones
– Galaxy S8, Galaxy S8+, Galaxy S8 Active, Galaxy Note8, Galaxy S9, Galaxy S9+, Galaxy Note9, Galaxy S10, Galaxy S10 5G, Galaxy S10+, Galaxy S10e, Galaxy Note10, Galaxy Note10+, Galaxy Note10 5G, Galaxy Note10+ 5G, Galaxy A90 5G, and Galaxy Fold

▷ Tablets
– Galaxy Tab S4, Galaxy Tab S5e, and Galaxy Tab S6

※ Available devices may differ by country or region.
※ The features that are available may vary slightly by model. We are planning to provide software updates to expand the availability of the service.

More information can be found here, under the General Enquiry menu.

If your phone is on the list above, and Samsung Dex is still not working then continue to the next solution.

Want to use Samsung Dex for playing fullscreen games? Read our article on gaming with Samsung Dex (includes recommended controllers!)

Dex works best on S9 and newer models, especially when you use a lapdock. Upgrading your phone might be the solution here!

5 – Update Your Phone’s Software & Download the Patch:

Most phones will automatically update, but you haven’t got around to it, I recommend checking for software updates.

Dex is a relatively new feature, so you should always check for software updates. If your phone’s operating system is updated, according to Samsung’s website, you might need to install the Samsung Knox update.

6 – Make Sure Phone is in High Performance Mode

In order for Samsung Dex to work, the power mode on your phone needs to be set to high performance.

Samsung Dex requires a lot of power, and might not launch if your phone is low on battery or has a faulty battery. Hence using an adapter that has power is recommended.

In most cases, an alert will appear asking for you to toggle from battery saving to high performance. It’s worth a shot.

7 – Manually Switch to Dex Mode on Your Phone

Sometimes, your phone won’t automatically switch to Samsung Dex mode, even if it’s connected to a USB-C to HDMI adapter.

In that case, you might need to manually switch to Dex Mode, which should be available on the drop-down menu.

For example:

If your phone starts screen-mirroring mode but shows this notification, then all you have to do is tap the notification to start Samsung Dex. It should get Samsung Dex working smoothly.

Another thing that you can try is going into your phone’s connection settings, find HDMI mode, and switch from mirroring to Dex.

Still not working?

8 – Try Using Your Original Phone Cable

I know, it sounds too simple, but it has worked for a few people. If Samsung Dex isn’t working then you might have a faulty USB-C cable. 

One solution that helped a friend was he switched back to the original USB-C cable that came with his phone, and Samsung Dex started right away.

It’s something worth trying out, at least. When in doubt, you can always buy another USB-C cable to test it. Another simple trick is to simply unplug all devices and cables and reconnect them, sometimes that works.

9 – Display not Compatible with Dex

Maybe your phone and the adapter are both fine, and the problem is with your display. Samsung Dex is only compatible with HDMI monitors and displays that have FHD at a 16:9 ratio.

If you’re trying to use a VGA adapter, it probably won’t work. You might be able to get Samsung Dex working with a VGA-only monitor if you use an active VGA to HDMI hub (a hub that has external power), like the hubs we recommended earlier, but it’s probably not the best solution.

If Samsung Dex is not working on your current monitor, test it with another one, or a TV. While some monitors aren’t compatible with the mode, most TVs are compatible.

From what I can gather, for your monitor to work with Samsung Dex, it needs to be HDMI-ready and support 16:9 ratio, with a minimum resolution of 1600×900.

Monitors that have only one port, whether VGA, DisplayPort, or something else besides HDMI, Samsung Dex probably won’t work.

10 – Double Check the Video Source on Display

Now, if you know the display works, but it’s not finding your phone, make sure the source settings are correct. Make sure you chose the right HDMI port in the video source menu. Double-checking and resetting all the connections won’t hurt either.

Other Solutions:

Try Samsung Dex on Windows or MAC OS

Here’s the link to Samsung Dex on PC. 

If Samsung Dex is not working automatically, one thing that you can try is downloading the software and testing it on your PC or Mac.

The only problem with this method is only the newer Samsung phones are compatible, from Note 10 to the latest Galaxy S20 Ultra.

While S9 to S10e can use Dex on PC through a software update, the older phones, such as my S8 (cry) are not compatible.

When connected to an HDMI display via an adapter, my S8 launched Samsung Dex, but it does not work with the PC version of Dex.

Nevertheless, if you have one of the compatible phones, Samsung Dex on the PC can be quite useful. It allows you to use apps that are only available on your phone or you can use two screens at once.

You also don’t need an HDMI cable for Dex on PC, you just need to use the USB port, which is great. Pretty convenient.

Can You Use Samsung Dex Wirelessly?

Yes. You can only use Samsung Dex wirelessly with a Miracast adapter with the S20 and Note 20 series. For older generations, a USB-C to HDMI dongle is required.

I wrote about the steps needed to get that working over here.

Conclusion:

If you run through this checklist, and Samsung Dex still does not work, then the problem is likely a glitch with your phone.

I recommend bringing it in to be serviced or getting a replacement. The good news is Samsung Dex usually starts with most modern phones, and it’s a mode you should be aware of and use.

It’s not only fun but also pretty convenient, and it can help keep you productive, especially with a Bluetooth mouse and keyboard.

Thanks for taking the time to read this quick tutorial. I hope it helps you with your Samsung Dex not starting issues. Leave a comment below if you have any questions or suggestions.