How to Fix a PC That’s Not Turning On

You hit the power button… and nothing happens. No lights. No fans. No boot. Before you assume your PC is dead, this guide walks you through the most common reasons a computer won’t turn on — and how to fix them safely.

Before You Start (Important)

• Turn the power supply switch OFF.
• Unplug the power cable from the wall.
• Hold the power button for 10 seconds to discharge leftover power.
• Never open a power supply — it can retain lethal voltage.

Step 1: Check the Basics (Most Common Fix)

• Plug the PC directly into a wall outlet.
• Try a different outlet if possible.
• Replace the power cable if you have a spare.

Step 2: Check the Power Supply Switch

• Locate the switch on the back of the PC.
• Make sure it’s set to ON ( | ).
• Flip it OFF, wait 10 seconds, then turn it back ON.

Step 3: Look for Any Signs of Life

• Motherboard LEDs lighting up
• Fans spinning briefly
• RGB flashing for a split second

• No response at all: likely PSU or power issue.
• Flash then off: protection shutdown or short.
• Fans spin but no display: component or POST issue.

Step 4: Check the Power Button Wiring

If pressing the power button does nothing, the front-panel power switch cable may be loose or misaligned.

• Locate the motherboard’s front panel header.
• Confirm the POWER SW connector is installed correctly.

Step 5: Reseat Power Cables

• 24-pin motherboard power cable
• 8-pin (4+4) CPU power cable near the top of the board
• GPU power cables (if installed)

Unplug each one fully and reconnect until firmly seated.

Step 6: Minimal Boot Test

Disconnect everything except:

• Motherboard
• CPU + cooler
• One RAM stick
• Power supply

If the system powers on now, one of the removed components is causing the issue.

Step 7: Reseat the RAM

• Remove all RAM sticks.
• Install one stick in the recommended slot (usually A2).
• Test each stick individually.

Step 8: Check Debug LEDs or Beep Codes

Many modern motherboards include CPU, DRAM, VGA, and BOOT LEDs. If one stays lit, it points directly to the problem component.

Step 9: Check for Shorts

• Loose screws under the motherboard
• Incorrect standoff placement
• Metal objects touching the board

Step 10: When to Suspect the Power Supply

• No lights or fan movement at all
• System instantly shuts off
• Known-good outlet and cable don’t help

*Disclaimer: Its always best to test your Power Supply before buying a new one.

FAQ

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