Laptops have forever changed where and how we work, and while they give us that freedom, it's still incredibly useful to be connected to a larger monitor (or two) when I'm working at my desk. As I get older and my vision deteriorates, it's so nice to be able to see everything I need to see at once without straining my eyes too much.
However, monitors, like laptops, are ultimately just machines, which means that sometimes they don't always work as expected. Getting a “display not detected” error message on your monitor is quite annoying, so I spoke to display manufacturers Asus and ViewSonic to get answers on why this might happen and how to fix it.
“Generally, there are no shortcuts or hidden tricks when a user receives a 'display not detected' signal from their monitor,” said Jenny Lopez, senior product manager for monitors at ViewSonic. However, there are a few things you can do, from quickly checking your connection to diving into graphics and system settings, Lopez told me.
So, before you go upstairs and throw your monitor off the balcony, here are a few simple steps to get your monitor working again.
Make sure it's turned on and connected
The first thing you should try is also the simplest: make sure your monitor is powered on and check if the cable is properly connected to your computer. Power cords tend to come loose, as do monitor cables, so make sure they are securely attached. This is a simple first step, but you might be surprised how often one of these turns out to be the culprit.
I can't tell you how much time I spent yelling at my monitor and computer for being stupid and broken, even though the whole time something was just wired wrong. And one day I spent half an hour troubleshooting why my monitor wasn't receiving power, only to realize that I had accidentally turned off the power strip. So yes, start by checking the power and connections. This is also a good time to turn everything off and on again. Sometimes a reboot is all that is needed to get everything working properly again. Also, make sure that if you're using a dock or hub, everything there is connected correctly (and turned on if necessary).
Make sure you are using the correct input
Make sure your display is set to the input you are using.
If everything is connected correctly, check the inputs on your monitor. Most modern monitors have several input options for connecting to a computer. But in order for your computer to display correctly on your monitor, the monitor itself must be on the correct input.
Most monitors have a physical button that allows you to switch inputs on the monitor itself, but there are some that can use a remote control instead. In any case, no matter which input on your monitor the cable coming from your computer is connected to, that is the input you will need to select in order for everything to display correctly. It's rare, but on some higher-end monitors the input options may be hidden under multiple layers of settings, but in general switching input should be relatively simple.
Many monitors have a choice of inputs. From left to right: HDMI (x2), DisplayPort and USB-C.
Today the most common type of display connection is HDMI. Another common input is DisplayPortor even Mini DisplayPort, but it is typically used by gamers, graphic designers, and other content professionals. While you can still find them on laptops, manufacturers have largely moved to USB-C as the display output of choice due to its small size and flexibility as it can be used for power, data, video and audio through a single thin cable.
However, Not all USB-C ports and cables have the same capabilities. For example, the USB-C cable that came with your phone or tablet can only be used to charge devices. Likewise, if your laptop has multiple USB-C ports, it's possible that only one of them supports display output. If this is the case, try moving the cable to a different USB-C port and, if possible, use the cable that came with the monitor or one that you are confident can be used for display output.
At this point, you should also consider resetting your monitors completely. Open the OSD menu and look for anything that says “Reset to original settings” or something similar. Resetting your monitor to its original settings may fix the situation, although you'll have to go back and redo any changes you made that you really need, such as power management or color temperature.
Read more: What is USB-C and what do all those numbers mean?
Inspect the cable
If you've completed the first three steps and still don't see anything on your screen, you should physically inspect the cable and the ports themselves. Check for cuts or abrasions around the edges. It's not uncommon for something to slip along a cable or for it to become compressed and cause damage, especially in an office setting or if you've recently moved your desk.
Be sure to inspect the ends of the cable. Regardless of the display cable type, there will be small metal pins at the end of the cable or in the monitor port. If any of these pins are bent or damaged, it can cause problems.
Also see: Best HDMI Cables
Check on another laptop or monitor.
If you don't see any physical damage to the cable or monitor, there may be an invisible problem. To make sure, connect your computer to your monitor using a cable that you know works. If the new cable works, there is a problem with the old cable. You can also try connecting another computer or device to the monitor. If you suddenly receive an image, then there may be a problem with your computer's connection.
If they still don't work, try connecting to a different monitor if you have access to one that you know works. Again, if the new monitor works, you have identified the problem.
Reset and update the software
Once you've completed all the other steps listed here, it's time to think about updating your software. While display-related software errors are rare, they are starting to appear more frequently, especially with Nvidia graphics cards.
“Over the past few years, there have been many cases of display and graphics card incompatibility, especially on POST. [power-on self-test] – says Juan Guerrero, senior technical product manager at Asus. – This means that initially you may not see any image until the OS boots. This may be annoying or confusing for some users and may require a VBIOS update.” This applies in particular to numerous Nvidia-based graphics cards, he added.
In most cases, updating the software can solve the problem. Start by making sure your computer has all available updates installed. Sometimes updates for your monitor may come from the operating system, Windows or MacOS, so updating your laptop to the latest version can help.
Windows users sometimes need to update the drivers of the graphics card (GPU) itself. The best way to do this is to use dedicated software for your GPU. Intel, Nvidia, AMD, or whoever made your GPU will install software on your computer to update it to the latest drivers.
Buy a new monitor
If none of the above steps resolve the issue, you may need a new monitor. Luckily, it's not hard to find a good option that suits your needs, whether it's office work, games or portable display for moving around the house or for travel. There are even some good, cheap monitors accessible. Plus, monitors seem to be on sale all the timeso it's pretty easy to find it all year round for less than full price.
