The screen is black, or nothing comes out of the speakers. Either way the first thought is “it's broken.” This article answers three questions — what you can establish in the next three seconds, what a repair costs if it comes to that, and what order to work in.
1. Three seconds first. Press Windows logo key + Ctrl + Shift + B. A beep or a flicker means the PC is on and only the display is out.
2. That result is what splits the bill. A display or sound problem often ends in a settings panel at no cost; no reaction at all points at power, which is a different conversation.
3. If it does go to service, the logic board is covered for two years under Samsung's Korean warranty terms (12 months on the computer, 24 on the logic board, 12 on a laptop display).
Each of the three, worked through below.
Three seconds first — is the PC alive?
Step two of Microsoft's blank-screen document is a single key combination. The point is that it does not fix anything — it tells you whether the machine is alive.
Windows logo key + Ctrl + Shift + B
The combination restarts the graphics driver, and the document adds:
“If it's successful, you'll hear a beep and see the screen flicker.”
— Microsoft Support, “Troubleshooting blank screens in Windows”
The reaction decides where to look next.
| If you get | What it establishes | Where to go next |
|---|---|---|
| A beep or a flicker | The PC is on; the problem is graphics | Step 3 of the display list below (display mode) |
| The security screen from Ctrl + Alt + Del | Windows is running; only the display is blocked | Restart Explorer from Task Manager |
| Nothing at all | This cannot be told apart from “won't turn on” | When the computer won't turn on |
| The third row's “cannot be told apart” is our judgement. The document does not say so. | ||
Those three seconds matter because the two branches cost different amounts. Narrowed to display or sound, the fix is often a setting or a driver; no reaction at all points at power or the board, which usually means service.
Display — Microsoft's five basic steps
| # | What to do | What it rules out |
|---|---|---|
| 1 | Check connections — power and charging, and an external monitor's cable and power | Cables come first |
| 2 | Wake the display — Windows + Ctrl + Shift + B | A beep or flicker means the PC is alive |
| 3 | Check the display mode — Windows + P, then P again and Enter | Output going to another screen |
| 4 | Ctrl + Alt + Del — if the security screen appears, restart Windows Explorer from Task Manager | The security screen appearing is itself a sign that Windows is running |
| 5 | Force a restart — hold the power button for 20 seconds | Last resort — unsaved work is lost |
| The advanced steps that follow run: check hardware connections → safe mode (force shutdown with a 10-second press, repeated two or three times) → update or roll back the graphics driver → restart Explorer (Ctrl + Shift + Esc) → system restore. | ||
Steps two and four show what kind of list this is. Neither repairs the display — both report how much of the machine is alive.
Sound — the first step is where the output goes
The audio document has a clear order too, and it does not start with drivers. It starts with where the sound is going.
| # | Microsoft's fix | How to read it |
|---|---|---|
| 1 | Check speaker output — Start > Settings > System > Sound, and select the right output device | “Make sure it isn't muted and the slider is up” is written alongside |
| 2 | Set the default playback device — right-click the device and set it as default | A different point from step 1 — “selected now” and “the default” are separate |
| 3 | Turn off audio enhancements — set Audio enhancements to Off in advanced settings | The feature that shapes sound can block it |
| 4 | Run the automated audio troubleshooter — in the Get Help app | Last |
| The document has no separate step for cables, the volume mixer, or restarting the audio service, so none appear here either. | ||
Step one of the display document and step one of the audio document ask the same question — where is the output going right now? If you run two monitors, or connect and disconnect Bluetooth earphones often, it frequently ends in that one box.
What a repair costs — panel or board
If none of the steps bring the display back, it is hardware. What decides the bill is which part it is and whether that part is still covered.
| Item | Warranty | Within the period |
|---|---|---|
| Computer | 12 months | Performance or function failures in normal use are free |
| Logic board | 24 months — core component | Free for two years from purchase |
| Laptop display | 12 months | Free |
| All-in-one PC LCD/LED panel | 24 months — core component | Free |
| Samsung's published warranty terms for Korea. Terms differ by manufacturer. Damage from impact or a drop is chargeable regardless of the period. | ||
The detail that actually moves money is that a laptop display is covered for 12 months while the logic board is covered for 24. On an 18-month-old laptop, a panel failure is chargeable and a board failure is not. Which is why it is worth telling the service centre what you already established — “the key combination did produce a beep” says more than “the screen is black.”
On a Mac the order is reversed
Apple's document is much shorter, and it runs the other way.
| # | Apple's step | How it differs from Microsoft |
|---|---|---|
| 1 | Power off and on — “press and hold the power button for up to 10 seconds, until your Mac turns off” | The forced restart that is Microsoft's last step is Apple's first |
| 2 | Start up from macOS Recovery | If Recovery appears, repair the startup disk with Disk Utility, then reinstall macOS if that fails |
| 3 | If Recovery does not appear — revive or restore the firmware on Apple silicon and T2 models | If you use an external monitor, suspect the monitor itself, the document says |
| 4 | If nothing works, contact service | The last step is the same at both companies |
| On laptops with Touch ID, the document says to hold the Touch ID button. | ||
For the same blank screen the two companies' first steps are opposites. Microsoft establishes whether the machine is alive; Apple powers it off and on. Neither document claims the other is wrong — but following the document for your own device is the safer choice.
If there is no sign of power at all, go to when the computer won't turn on; if it starts but crawls, a slow computer. If it starts and then dies, shutting down suddenly; if only the internet is out, when the internet won't work.
Questions that come up
I pressed the key combination and nothing happened
The document only describes success — a beep or a flicker — and says nothing about no reaction. The flow of the list points to the next steps (Windows + P, Ctrl + Alt + Del). If those give nothing either, the problem has not been narrowed to the display and power needs checking too.
I run two monitors and only one is black
Step three is exactly that case — Windows + P to cycle the display mode. Apple's document separately says to suspect the monitor itself when an external display is in use. In that case the relevant warranty is the monitor's, not the computer's.
I unplugged my earphones and the speakers still don't work
Steps one and two of the audio document cover it. “The output device selected now” and “the default playback device” are separate settings, which is why the document splits them. If it ends here, the cost is nothing.
Is holding the power button for 20 seconds safe?
Microsoft puts “hold the power button for 20 seconds” as the last of the five basic steps, and in the advanced procedure asks for a 10-second forced shutdown repeated two or three times to reach safe mode. Both come after the earlier steps, and unsaved work is lost.
Can I open the case and check the cables?
None of the three documents contains a step that opens the machine. External cables and external monitor connections are as far as they go; after that it is service. Handling judged to be outside normal use becomes grounds for a chargeable repair.
What we read into it
Placed side by side, the character of these documents shows. In Microsoft's display list, steps two and four report rather than repair; the first step for display and for sound asks the same question about where output is going; and for the same blank screen the two companies' first steps are opposites. All three are ours from the comparison; no document explains itself that way.
One more: Microsoft's Windows + Ctrl + Shift + B also appears in the “won't turn on” document. The same combination spanning both reads as Microsoft treating the two symptoms as overlapping.
Sources
- Microsoft Support (tier 3, manufacturer document) — Troubleshooting blank screens in Windows (checked August 2026). Source for the five basic steps and their order, Windows + Ctrl + Shift + B with “if it's successful, you'll hear a beep and see the screen flicker,” the Windows + P sequence, restarting Explorer after Ctrl + Alt + Del, the 20-second power button hold, and the advanced procedure.
- Microsoft Support (tier 3, manufacturer document) — Fix audio issues when no sound plays from speakers or headphones (checked August 2026). Source for the four fixes and their order, the “select the right output device” and mute/slider guidance in step one, the default playback device in step two, audio enhancements in step three, and the automated troubleshooter in step four.
- Apple Support (tier 3, manufacturer document) — If your Mac starts up to a blank screen (checked August 2026). Source for “press and hold the power button for up to 10 seconds, until your Mac turns off,” the macOS Recovery → Disk Utility → reinstall sequence, firmware revive and restore on Apple silicon and T2 models, the guidance to suspect an external monitor, and the Touch ID button.
- Samsung Electronics (tier 3, manufacturer document) — Warranty information (checked August 2026). Source for the 12-month computer warranty, the 24-month core-component warranty on the logic board, 24 months on all-in-one panels, 12 months on laptop displays, and impact damage being chargeable.
Where to check further
- The warranty on your own device — terms differ by manufacturer. Samsung publishes them under warranty information; Apple lets you pick a model on its support pages.
- Diagnosing the monitor or speakers themselves — this article read only the computer-side documents. External displays and audio devices belong to their own manufacturers' documentation.
- Differences between Windows 10 and 11 — whether the display steps are identical across versions can be checked by selecting the version on Microsoft's support page.
Written as of August 2026. The display and audio steps come from Microsoft Support, the Mac procedure from Apple Support, and the Korean warranty terms from Samsung's warranty page; what emerged from placing the three documents together is marked as ours. If you suspect a hardware failure, do not open the machine — take it to the manufacturer or a service centre.
