Is your computer powering up only to shut down immediately, or does it fail before the operating system even loads? If this is happening, the issue could range from an electrical short to a serious hardware malfunction.

How to Fix a Computer That Won’t Stay Powered On

Resolving this issue may take just a few minutes or several hours, depending on what's causing the system to shut down shortly after startup.

1. Investigate any beep codes you hear during startup. These sounds can provide vital clues about which component is failing.

   If the beep code doesn’t solve the issue, continue with the steps below.

2. Confirm the power supply’s voltage switch is set to the correct setting for your region. Mismatched voltage settings can prevent proper operation and may cause the computer to power on briefly before shutting down.

   While incorrect voltage often prevents the PC from turning on at all, it can also lead to immediate shutdowns.

3. Ensure your computer is adequately cooled. Overheating can trigger automatic shutdowns. Visit the linked guide for simple cooling solutions anyone can apply.

4. Look for internal electrical shorts. If the system powers on for only a second or two before cutting off, a short circuit inside the case could be to blame.

5. Evaluate the power supply unit (PSU). Even if the computer turns on momentarily, the PSU might still be defective. Power supplies are common culprits in unexpected shutdowns.

   Replace the PSU if testing reveals any faults.

6. Examine the front-panel power button. If it's stuck or shorting against the case, it may be triggering repeated shutdowns.

   Replace the button if testing shows it’s faulty or behaving abnormally.

7. Reconnect all internal components. Over time, vibrations and thermal expansion can loosen connections. Reseating ensures solid contact.

   Perform the following:

   • Unplug and reconnect all data and power cables inside the PC
   • Remove and reinsert RAM modules
   • Reseat any expansion cards (like GPU or sound cards)

8. Reinstall the CPU only if you suspect improper installation or that it has become dislodged.

9. Reset the CMOS to restore BIOS settings to factory defaults. Incorrect BIOS configurations can prevent normal booting.

   If resetting doesn’t help, consider replacing the CMOS battery.

10. Boot with only essential hardware connected. Strip the system down to the basics: motherboard, CPU, one RAM stick, and PSU.

    If the PC stays on with minimal hardware, move to Step 11.

    If it still shuts down, proceed to Step 12.

11. Gradually reinstall non-essential components, one at a time, testing after each addition.

    Since the system runs with only essential parts, the fault lies in one of the removed components. By reintroducing them individually, you can isolate the problematic device.

    Once identified, replace the faulty part.

12. Use a POST (Power-On Self-Test) card to diagnose the issue. When the problem persists with only core hardware, a POST card can pinpoint which component is failing during startup.

    Skip to Step 14 if you don’t have or don’t want to buy a POST card.

13. Swap out each essential component (motherboard, CPU, RAM, PSU) with a known working equivalent, one at a time. Test the system after each replacement to identify the defective part.

14. If all previous attempts fail, it’s time to consult a professional repair service or contact your manufacturer’s support team.

    Without a POST card or spare parts, identifying the faulty component becomes nearly impossible. In such cases, expert assistance with proper diagnostic tools is your best option.

Why Does My Computer Keep Shutting Down?

Multiple factors can cause a PC to turn on and then immediately power off. A structured troubleshooting approach, like the one outlined above, is crucial. Common causes include:

• Damaged or defective power cables
• Hardware or driver incompatibility
• Components not securely seated inside the case
• Failing power supply unit

If your monitor keeps switching off, check the connection to your PC and ensure it's not overheating. Inspect cables, clean the screen and vents, and improve airflow around the display.

10. How can I disable unnecessary startup programs on Windows? Open Task Manager, navigate to the Startup tab (or Startup apps in Windows 11), sort by Status to see enabled apps, then right-click any unwanted program and choose Disable.
11. Can I power my PC on or off remotely? Yes. After remotely accessing your Windows PC, use the shutdown command to turn it off. For remote wake-up, ensure Wake-on-LAN is enabled in BIOS and configured properly.
12. What should I do if my PC powers on but shows no display? Shut down the computer by holding the power button for 3–5 seconds. Once fully off, restart it to check for normal booting. If the issue persists, verify the PSU voltage setting and inspect for internal electrical shorts.

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