Your PC Has Sound but No Display – 7 Things to Check Before Assuming Your Monitor Is Dead

You power on your PC.
The monitor stays black and shows “No Signal.”

But you can hear Windows booting.
The keyboard reacts.
Something is clearly running.

At this moment, most people think:

“My monitor must be broken.”

In reality, the monitor is often not the problem at all.
Before replacing hardware or visiting a repair shop, run through these 7 critical checks first.

Quick Reality Check: Is the PC Actually Running?

Before anything else, confirm that Windows is truly alive.

Quick Check

Press Caps Lock or Num Lock on your keyboard.

  • If the indicator light turns on and off →
    ✅ Your system is responsive. This is a display-only issue.

  • If there’s no response →
    ⚠️ The system may be stuck during boot.

This simple check prevents chasing the wrong problem.

1️⃣ The Display Output Is Going to the Wrong Screen

This is the most common cause by far.

If you’ve ever:

  • Used dual monitors

  • Connected a TV or projector

  • Used Remote Desktop

Windows may still be sending the display signal somewhere else.

How to Check

Press:

Windows + P

“Blind Operation” Trick (When You Can’t See the Menu)

  1. Press Windows + P

  2. Press Up or Down Arrow once or twice

  3. Press Enter

  4. Repeat 2–3 times

In many cases, the screen suddenly reappears.

2️⃣ The Monitor Cable Is Plugged into the Wrong Port

This happens constantly on desktops with dedicated graphics cards.

Common Mistake

  • Cable is plugged into the motherboard port

  • Actual video output comes from the graphics card

Result:

  • PC boots normally

  • Monitor shows “No Signal”

🔍 Visual Tip (Beginner-Friendly)

On most desktop towers:

  • Vertical ports = Motherboard

  • Horizontal ports = Graphics card

Always plug the monitor cable into the horizontal ports.

This single detail fixes an incredible number of “dead monitor” cases.

3️⃣ Monitor Input Source or Cable Issues

Sometimes the monitor is simply listening to the wrong input.

Check:

  • HDMI 1 vs HDMI 2

  • DisplayPort vs HDMI

Also Test the Cable

Cable problems are more common than people expect:

  • Old HDMI/DP cables

  • Cheap cables

  • Internal wire damage

👉 If possible, test with a different cable before assuming anything is broken.

4️⃣ Graphics Driver Reset (⭐ The Magic Shortcut)

After:

  • Windows updates

  • Sleep/hibernate crashes

  • Forced shutdowns

The graphics driver can lock up without crashing Windows.

The Shortcut

Ctrl + Shift + Windows + B

What happens:

  • You hear a beep

  • The screen briefly flashes

  • The graphics driver restarts instantly

👉 Over 80% of software-based black screen issues are fixed here.

Remember This

When the screen is black, don’t panic.
Try Ctrl + Shift + Win + B first.
It’s Windows waking the graphics card back up.

5️⃣ Use the BIOS Logo to Identify the Real Cause

This is the fastest way to separate hardware vs software issues.

When powering on, ask:

Did you see the manufacturer logo (Dell, HP, ASUS, etc.), even briefly?

Interpretation

  • ✅ Logo appears, then screen goes black
    → Monitor and cable are fine
    → Windows or graphics driver issue

  • ❌ No logo at all
    → Cable, port, or monitor hardware issue likely

This one check eliminates a lot of guesswork.

6️⃣ RAM Seating Issues (⚠️ Handle with Care)

Less common, but very real—especially if:

  • The PC was moved

  • Internal cleaning was done

  • The system is older

Loose RAM can prevent any display output.

Safety Rules (Important)

  • Unplug the power cable completely

  • Touch a bare metal part of the case (not painted) to discharge static electricity

  • Then reseat the RAM modules

⚠️ Static electricity can permanently damage components. Take this step seriously.

7️⃣ Pro Tip: The Flashlight Test (Backlight Failure Check)

If there’s sound but no image, the monitor backlight may have failed.

How to Test

  1. Turn off the room lights

  2. Shine your phone’s flashlight directly at the screen

  3. Look closely

Result

  • If you see a faint desktop image →
    ✅ Your PC is fine
    ❌ The monitor’s backlight has failed

This confirms you need monitor repair or replacement, not a PC fix.

Final Thoughts

When the screen goes black, it’s natural to blame the monitor.

But most cases come down to:

  • Output routing

  • Port selection

  • Graphics driver glitches

  • Cables and settings

Following these steps in order can save you from replacing functional hardware unnecessarily.

One Last Thing to Remember

When everything goes black:

Press Ctrl + Shift + Win + B first.
That single shortcut prevents a lot of panic—and wasted money.

📡 If your screen is working but your internet connection feels unstable, the issue may be related to network configuration rather than display hardware.
👉 You may also find this guide helpful:
“Wi-Fi Connected but No Internet — A Step-by-Step Troubleshooting Guide.”

🌐 If the display comes back but your browser still feels unusually slow, the problem may be related to browser settings or extensions, not your graphics hardware.
👉 See also:
“Why Chrome Suddenly Gets Slow — What to Check Before Clearing Cache.”

🖨️ If display issues were followed by printer or peripheral problems, driver or port conflicts may be affecting multiple devices at once.
👉 This guide may help:
Printer Connected but Not Printing – 9 Things to Check Before Reinstalling Drivers

This guide is also available in Korean.
If you prefer reading technical instructions in Korean, you can find the original version below.
소리는 나는데 화면이 안 나올 때 – 모니터 고장으로 착각하기 쉬운 PC·윈도우 점검 7가지