Why Is My Monitor Showing 'No Signal Detected'? (8 Fixes)

Having your monitor display a 'No Signal Detected' error can be incredibly frustrating, especially when you're in the middle of work, gaming, or streaming. You're not alone—this is one of the most common monitor issues reported by users across forums like Reddit and tech support communities. Whether it's a blank screen or a persistent error message, this problem can disrupt your day and leave you scrambling for solutions.

This issue often stems from simple connection problems, software glitches, or hardware failures. Based on user experiences and expert advice, we've compiled this guide to help you troubleshoot and resolve the problem quickly. You'll learn 8 actionable fixes—from checking cables to testing hardware—plus advice on when it’s time to upgrade to a new monitor.

By the end of this guide, you’ll either have your monitor back up and running or know exactly what to replace it with. Let’s dive into the causes and solutions to get you back on track!

Common Causes

• Loose or disconnected cables
• Incorrect input source selected
• Graphics card or driver issues
• Faulty monitor hardware
• Power supply problems

Troubleshooting Steps

1. Check All Cable Connections

Difficulty: easy | Time: 2 minutes

Start by ensuring all cables (HDMI, DisplayPort, VGA, or DVI) are securely plugged into both your monitor and computer. A loose connection is the most common cause of a 'No Signal Detected' error. Unplug each cable, inspect for bent pins or damage, and firmly reconnect them. Also, check the power cable to ensure the monitor is powered on—look for a power indicator light.

Why this works: Loose cables can interrupt the signal between your computer and monitor.

What you should see: If this fixes it, your monitor should display your desktop or a signal within a few seconds.

Warning signs: If cables are damaged or the power light doesn’t turn on, move to the next steps.

2. Verify the Correct Input Source

Difficulty: easy | Time: 3 minutes

Monitors often have multiple input options (e.g., HDMI 1, HDMI 2, DisplayPort). Use the monitor’s physical buttons or on-screen display (OSD) menu to cycle through inputs and select the one matching your connected cable.

Why this works: If the wrong input is selected, the monitor won’t detect the signal from your device.

What you should see: The screen should display your computer’s output once the correct input is selected.

Warning signs: If cycling inputs doesn’t work, the issue may not be with the input setting.

3. Test with a Different Cable

Difficulty: easy | Time: 5 minutes

Swap out the current cable with a spare HDMI, DisplayPort, or other compatible cable. Faulty cables can fail to transmit a signal even if they look fine. If you don’t have a spare, borrow one or purchase a reliable option like the AmazonBasics HDMI Cable.

Why this works: Damaged cables are a frequent culprit for signal issues.

What you should see: A working cable should restore the display immediately.

Warning signs: If a new cable doesn’t help, the issue might be with the ports or hardware.

Tools needed: Spare cable

4. Connect to a Different Device

Difficulty: easy | Time: 5 minutes

Plug your monitor into another device, like a laptop, gaming console, or another PC, using the same cable. This helps determine if the issue is with your computer or the monitor.

Why this works: If the monitor works with another device, the problem lies with your original computer’s output (likely graphics card or settings).

What you should see: A signal should appear if the monitor is functional.

Warning signs: No signal on another device suggests a monitor hardware issue.

Tools needed: Alternate device

5. Update or Reinstall Graphics Drivers

Difficulty: medium | Time: 15 minutes

Outdated or corrupted graphics drivers on your computer can prevent signal transmission. Visit your graphics card manufacturer’s website (NVIDIA, AMD, or Intel) to download and install the latest drivers. Alternatively, use Windows Device Manager to uninstall the driver, then restart your PC to let it reinstall automatically.

Why this works: Drivers act as the bridge between your hardware and software; issues here can block the signal.

What you should see: After updating, reconnect the monitor—it should display normally.

Warning signs: If drivers don’t fix it, there may be a deeper hardware issue.

6. Check Graphics Card Hardware

Difficulty: medium | Time: 10 minutes

If you have a desktop PC with a dedicated graphics card, ensure it’s properly seated in the PCIe slot. Power off your PC, unplug it, open the case, and gently press the card to secure it. Also, check if additional power connectors to the card are plugged in. Safety warning: Always unplug your PC and ground yourself to avoid static damage.

Why this works: A loose graphics card can fail to send a signal to the monitor.

What you should see: After reseating, the monitor should detect a signal on boot.

Warning signs: If the card appears damaged or doesn’t work, it may need replacement.

Tools needed: Screwdriver (for PC case)

7. Reset Monitor to Factory Settings

Difficulty: medium | Time: 5 minutes

Use the monitor’s OSD menu (via physical buttons) to perform a factory reset. Look for a 'Reset' or 'Default Settings' option. This clears any custom settings that might be interfering with signal detection.

Why this works: Incorrect settings can sometimes prevent signal recognition.

What you should see: Post-reset, the monitor may detect the signal automatically.

Warning signs: If resetting doesn’t help, the issue is likely hardware-related.

8. Test Monitor on a Different Port

Difficulty: medium | Time: 5 minutes

If your monitor and computer have multiple port types (e.g., HDMI and DisplayPort), try a different port on both devices with an appropriate cable. Ports can fail independently of the device.

Why this works: A faulty port can cause signal loss even if other hardware is fine.

What you should see: Switching to a working port should restore the display.

Warning signs: If no ports work, the monitor’s internal hardware may be failing.

Tools needed: Alternate cable if needed

When to Upgrade

If none of the above steps resolve the 'No Signal Detected' issue, it’s time to consider whether your monitor is worth repairing or if replacement makes more sense. Key signs of permanent failure include no power indicator light, no response on any device or port, or visible damage like cracks or burn marks on the screen or ports. If your monitor is over 5-7 years old, internal components like the power supply or display panel may have reached the end of their lifespan, and repair costs can often exceed $100—sometimes close to the price of a new, more reliable model.

Check your monitor’s warranty status first; many manufacturers offer 1-3 years of coverage for hardware defects, and a claim could save you money. However, if the warranty has expired and repair quotes are high, upgrading is usually the better choice. New monitors offer improved resolution, refresh rates, and energy efficiency, often justifying the cost over a risky repair. Safety is also a concern—avoid DIY fixes on internal components unless you’re a trained technician, as there’s a risk of electric shock.

Red flags that scream 'upgrade' include frequent signal loss even after fixes, flickering displays, or outdated technology that no longer meets your needs (e.g., low resolution). At this point, investing in a new monitor will save you time and frustration in the long run.

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Prevention Tips

• Regularly check and secure all cable connections to avoid loose plugs.
• Avoid frequent unplugging of cables to reduce wear on ports.
• Keep graphics drivers updated to prevent software-related signal issues.
• Use a surge protector to protect your monitor from power surges.
• Clean dust from ports and vents to prevent overheating and hardware stress.