It can be very frustrating when you switch on your PC, and the monitor doesn’t light up as usual. Instead, it displays a “no signal” message, which is the last thing you want to encounter, especially if you want to do something important on the computer. So, you want to resolve the problem as soon as possible, but first, you have to understand why it happened.
There are several causes of the no signal problem, which we can narrow down to four primarily. One is that your monitor could have a mechanical issue preventing it from receiving input from the PC. Loose or defective video cables and incorrect input sources could also trigger this problem. If you happen to rule out these three causes, your PC must be the root of the problem.
We’ll discuss all these in detail below and provide a solution for each. Read on to learn what you should do to resolve this annoying no signal issue.
Four Reasons Why Your Monitor Says No Signal
Reason #1: Loose or Defective Cables
One possible cause for the no signal problem is a loose cable connection between your PC and the monitor. The video cable could also be firmly connected, but it’s damaged. Either way, the no signal problem will be triggered. Here’s what you should do to rule out this possibility:
- Unplug the cable and then plug it back. Make sure that you connect it firmly – push it in fully.
- Check if dust and debris have clogged up the ports, interfering with the connection.
- Inspect the cable for any damages (Look for nicks, bends, and drying). You can also rub your fingers on the cable to try and feel any abnormal issues.
- Test your cable on a different monitor.
- Use your TV screen if it has corresponding ports with your PC. Many modern TV screens have HDMI and VGA ports.
- You can also ask your friend or neighbor for assistance if you can’t use your TV or find a spare monitor.
- If your cable isn’t working with a new monitor, it’s likely the cause, and you need to buy a replacement.
Reason #2: Incorrect Input Source
Check and ensure you’ve chosen the right input source. Before selecting the correct input source for the monitor, you must understand what ports your monitor and the PC have.
Most monitor displays today support multiple input sources; HDMI, VGA, DVI, and even DisplayPort, which allow for connecting multiple devices to the display simultaneously. So, use the following steps to choose the right input source for your monitor:
- Make sure that your monitor and PC are both turned on.
- Press the “Menu” button on the edge of the monitor.
- Go to “Input Source” and choose the correct input source.
If you’ve connected your PC to the VGA port on your monitor, then set the input source as VGA. And if it’s DVI or DisplayPort, then it is the input source to exactly that.
Reason #3: Bad Monitor
Your monitor could have developed a mechanical problem preventing it from receiving input from the computer. Usually, you won’t see anything on a monitor that has gone bad. In other words, it won’t turn on and will be completely black.
However, you have to rule out the possibility that the monitor has a hardware fault causing the no signal problem. Here’s what to do:
- Test with another device. Connect another device such as a game console if your monitor has an HDMI port and see if it displays something.
- Use another monitor. Connect your PC with another monitor and see if the no signal problem persists. You can use your TV if it has a corresponding port with the PC, such as VGA or HDMI.
If the monitor is working with another device, it means that it’s not the cause of the no signal error. On the other hand, if the monitor remains blank and another monitor is working with the PC, then the problem could be something to do with the monitor resolution.
It could have suddenly lost resolution after you’ve changed the settings yourself. In that case, reconnect the monitor, switch on the PC and wait for about 15 seconds. The Windows will return to the previous resolution. If it happens automatically, connect your PC to a second screen and set the resolution to that of your original monitor. Consult the monitor’s user manual for the correct resolution.
After testing with another device, the monitor still displayed no signal message. You used another monitor, and it worked. In that case, your monitor is bad, and you have to take it for professional repair or, better yet, purchase a new one.
Reason #4: The PC has a Problem
The no signal message on your monitor can also indicate that your PC isn’t sending input. If you’re sure that the monitor and the cables are fine and connected to the correct input, the problem must be with the PC.
There could be many reasons why your computer isn’t displaying anything on the monitor. One is a loose graphics card if your PC has it. First, check and make sure that the display cable is connected to the graphics card and not the motherboard video input.
Conversely, if your PC has an integrated graphics card, the display cable should be plugged into the motherboard’s display input.
You must rule out that possibility as well, and here’s what to do:
If the issue persists, don’t worry! There are a couple of fixes for you to try. First, the graphics card could be faulty. In that case, you might need to buy a replacement.
- Switch off your PC and disconnect all the cables, including the power cord and peripheral devices.
- Open the computer case and locate the graphics card on the motherboard.
- Remove the card and then insert it in its slot firmly.
- Close the case and then press and hold the power button for 30 to 60 seconds.
- Plug back the power and the monitor cables to the PC and turn it on.
There is also an improper connection between your PC and its RAM sticks, which triggers the no signal message on the monitor as the PC isn’t getting any power. Here’s what to do:
- Turn off your computer.
- Unplug the power cable and remove the case.
- Locate the memory slots and plug the stick(s) out.
- Re-sit the memory stick(s) back into its place.
- Plug back the power cable and turn on your PC.
If it doesn’t display anything yet, unplug the power cable and try using one memory stick if your motherboard has several. Re-sit the stick into a different slot. Also, try to switch the sticks around.
Unplug the power and remove the CMOS battery from the motherboard if the problem persists. Press and hold the power button for a minute to remove all the power. Put the battery back and turn on the PC.
If there’s no display, you need to check your components, for example, the power supply or even the CPU. We recommend that you take the PC to a professional to help diagnose the problem better and hopefully resolve it.
Why does my monitor say no signal? We’ve provided the most common causes for the no signal problem above. They include loose or defective video cables, incorrect input sources, and faulty monitors.
We have also provided possible solutions to each problem above. Seek professional help if you find out that your PC is the root of the problem and you can’t seem to resolve it on your own.