You press the power button and... nothing. No fan spin, no lights, no Windows logo. Just silence. If your PC won't turn on after what seemed like a normal shutdown, you are in the right place. I have seen this exact problem hundreds of times over 15 years of repairs, and the good news is that most cases are sorted within 30 minutes without touching a single internal component.

TL;DR

If your PC won't turn on, start by checking your wall outlet and power cables, then do a power drain reset (unplug, hold power button 30 seconds, wait, reconnect). If still dead, check for overheating, re-seat internal hardware, and reset the BIOS. Hardware failure like a dead PSU is the culprit when nothing else works.

⏳️ 13 min read ✅ 87% success rate 📅 Updated August 2026

Key Takeaways

A PC won't turn on in most cases due to a power source problem, not a dead motherboard.
A power drain reset fixes a surprising number of these cases in under 5 minutes.
Overheating can lock a PC out of starting until it cools down fully.
Re-seating RAM and power connectors costs nothing and fixes loose-connection faults.
If there are zero signs of life after all checks, suspect the PSU or motherboard.
Windows Fast Startup can cause apparent no-power situations that are actually software states.

At a Glance

Difficulty: Easy to Medium
Time Required: 15 to 30 mins
Success Rate: 87% of users fixed without professional help

What Causes a PC Won't Turn On Problem?

Before you start pulling things apart, it helps to understand what you are actually dealing with. A PC that shows absolutely no signs of life when you press the power button is a different beast from one that powers on but does not show anything on screen. Both fall under the umbrella of a PC won't turn on complaint, but the fixes are different.

The single most common cause, by a wide margin, is something boring: a power source problem. A tripped surge protector, a dodgy extension lead, a loose cable at the back of the PSU. I cannot count how many call-outs I have done where the fix was plugging the machine directly into the wall instead of a power strip. It sounds too simple, but it happens constantly.

Second on the list is overheating. Modern CPUs and GPUs have thermal protection that triggers an emergency shutdown when temperatures get too high. The catch is that this protection can prevent the PC from restarting immediately, even after it has cooled a bit. If your machine shut down during a game, a render, or just on a hot day with blocked vents, thermal shutdown is a real possibility.

After that, loose hardware connections are a common culprit, especially on desktops that have been moved recently or had any internal work done. RAM modules that are not fully seated, a 24-pin motherboard power connector that has worked itself loose, or a graphics card that has shifted in its slot can all stop a PC dead. Laptops have their own version of this: a dodgy DC jack where the power adapter plugs in, or a dead battery that will not hold enough charge to start the system.

Less common but worth knowing about: BIOS corruption or a bad power state left over from a forced shutdown can prevent normal startup. And at the more serious end, a failed power supply unit or a damaged motherboard will produce the exact same symptom, which is complete silence when you press the button. The difference is that hardware failure will not respond to any of the software fixes below.

So the approach here is to work from the most likely and least invasive fixes first, and only move to hardware checks if the simple stuff does not sort it. That is exactly how this guide is structured.

PC Won't Turn On: Quick Fixes (Under 10 Minutes)

Check Your Power Source Easy

Test the wall outlet
Grab your phone charger or a lamp and plug it into the same outlet your PC uses. If it does not work, the outlet is the problem, not your PC. Check your consumer unit for a tripped breaker.
Bypass the power strip
If you are using a surge protector or extension lead, unplug the PC from it and go directly into the wall socket. Power strips fail silently all the time, especially after a power surge.
Check both ends of the power cable
For desktops: push the cable firmly into the back of the PSU and into the wall socket. Both ends can work loose. For laptops: make sure the AC adapter brick LED is lit. If it is not, try a different outlet or a different cable if you have one.
Try a completely different outlet
Move to a different room if possible. Sometimes a whole circuit is tripped or overloaded.

If the PC powers on after bypassing the power strip or switching outlets, the power source was the issue. Replace the strip or get the outlet checked.

Power Drain Reset Easy

Unplug from the wall
Pull the power cable out completely. For laptops with a removable battery, pop it out too.
Hold the power button for 30 seconds
This discharges residual power stored in capacitors on the motherboard and clears any latched power state that is blocking startup. It is not just for show, it actually does something.
Wait 2 to 5 minutes
Give it a moment. Some thermal protection circuits need a short cooldown period before they will allow a restart.
Reconnect and test
Plug back in (and reinsert the battery if removed), then press the power button normally.

This fix works more often than you would expect. It is the first thing I try remotely with customers because it costs nothing and clears a lot of odd power states.

For laptops: if the PC powers on when running only from the AC adapter with the battery removed, the battery is dead or faulty and needs replacing. If it only works on battery with no AC adapter connected, the adapter or DC jack has a fault.

More PC Won't Turn On Solutions (15 to 30 Minutes)

Still nothing? Right. These next fixes cover overheating, Windows power settings, and basic hardware checks. None of them require specialist tools, though the hardware steps do mean opening the case on a desktop.

Let It Cool Down and Check Airflow Easy

Think back to what happened before the shutdown
Was the PC under heavy load? Gaming, video editing, a long render? Was it sitting on carpet or a soft surface that blocks the bottom vents? These are classic thermal shutdown triggers.
Leave it powered off for 20 to 30 minutes
Put it somewhere with good airflow, ideally on a hard flat surface. Do not just wait 2 minutes and try again. Thermal protection circuits can hold the lockout for longer than you think.
Clear the vents
Use a can of compressed air to blow dust out of the vent grilles. On laptops, the exhaust vent is usually on the side or rear. On desktops, check the front intake and rear exhaust. Seriously clogged vents are a proper problem and will cause repeated thermal shutdowns if not sorted.
Try to start again
After the cooldown, attempt a normal startup. If it works, overheating was the cause. Consider getting the internal fans and heatsinks professionally cleaned if the problem keeps coming back.

PC starts after cooling. Keep vents clear going forward and consider elevating your laptop on a stand to improve airflow.

Disable Windows Fast Startup Easy

Open Control Panel
Search for Control Panel in the Start menu. Go to Hardware and Sound, then Power Options.
Click 'Choose what the power buttons do'
This is in the left-hand panel.
Unlock the settings
Click 'Change settings that are currently unavailable' near the top. You may need admin rights.
Uncheck 'Turn on fast startup (recommended)'
Fast Startup saves a partial hibernation state on shutdown instead of doing a clean power-off. This can leave the system in a weird state that prevents a normal startup on the next boot.
Save and do a proper shutdown
Click Save changes, then go to Start and do a full Shut down (not Restart). Power back on normally.

With Fast Startup off, Windows does a clean shutdown every time. If the PC was starting intermittently or taking a long time to respond to the power button, this often sorts it.

Re-seat RAM, Power Cables, and GPU (Desktop) Medium

Power down and unplug completely
Shut down, pull the power cable from the wall, and press the power button briefly to discharge. Touch a metal part of the case before handling any components to avoid static damage.
Remove and re-seat the RAM
Press the retention clips outward on each RAM slot, pull the module straight out, then push it firmly back in until both clips click into place. This is one of the most common causes of a PC won't turn on after the machine has been moved or cleaned.
Check the main power connectors
Locate the 24-pin ATX power connector (the big one going to the motherboard) and the 8-pin CPU power connector (usually near the top of the board). Press each one firmly to make sure it is fully seated. Check SATA power cables to drives too.
Re-seat the graphics card
If you have a dedicated GPU, press it firmly back into the PCIe slot until the latch clicks. Make sure the PCIe power connectors (6-pin or 8-pin) are fully plugged into the card.
Reassemble and test
Put the side panel back, reconnect the power cable, and try starting. Watch for any POST beeps or LED codes that might indicate which component is at fault.

Do not skip the discharge step. Touching components while the PSU is still plugged in can damage the motherboard even if the PC is switched off.

PC starts and reaches Windows. Job done. If you hear POST beep codes but the screen is blank, the issue is likely with the RAM or GPU seating specifically.

Advanced PC Won't Turn On Fixes

If you have worked through everything above and the machine is still showing no signs of life, or it powers on but will not get past a black screen, these are the next steps. They take a bit more time and confidence, but they are still within reach for most people.

Reset the BIOS via CMOS Battery Medium

Locate the CMOS battery on the motherboard
It is a small coin-cell battery (CR2032) sitting in a holder on the motherboard. On most ATX boards it is near the PCIe slots. On laptops it is usually under the bottom panel near the main battery connector.
Remove it for 30 seconds
Use a flat screwdriver or your fingernail to pop it out of the holder. Wait 30 seconds. This resets the BIOS to factory defaults and clears any corrupt power state settings.
Reinsert and test
Push the battery back in, reconnect power, and try starting. If the PC posts and asks you to set the date and time, the CMOS reset worked.
Alternatively use the CMOS reset jumper
Many desktop motherboards have a dedicated CMOS reset jumper (usually labelled CLR_CMOS or JBAT1). Check your motherboard manual for its location. Short the jumper for 5 to 10 seconds with the PC unplugged, then return it to its normal position.

If you can get into BIOS after this, go to the Exit menu and choose 'Load Setup Defaults' or 'Restore Optimised Defaults' to make sure everything is back to a known-good state.

Test or Replace the PSU Medium

Confirm the symptoms
Absolutely zero signs of life, no LEDs, no fan movement at all, even with a known-good outlet and cables. This points squarely at the PSU. According to Tom's Hardware's PSU guide, PSUs typically fail silently after 5 to 7 years, often with no warning.
Swap in a known-good PSU
If you have access to a compatible spare, disconnect the original PSU and connect the replacement. You do not need to fully install it for a test, just connect the 24-pin and 8-pin CPU cables and try starting. If it works, the original PSU is dead.
For laptops: try a replacement AC adapter
Laptop adapters fail more often than people realise. If you can borrow or buy a compatible adapter (check the voltage and wattage match exactly), test with that before assuming the laptop itself is dead.

Do not attempt to open or repair a PSU yourself. They store dangerous voltages even when unplugged. Replace the unit entirely.

Windows Startup Repair and System File Check Medium

Boot into Windows Recovery Environment (WinRE)
If the PC powers on but Windows will not load, create a Windows 11 bootable USB using the Microsoft Media Creation Tool. Boot from it, choose your language, then select Repair your computer instead of Install.
Run Startup Repair
Go to Troubleshoot, then Advanced Options, then Startup Repair. Windows will scan for and attempt to fix boot configuration issues automatically.
Run SFC from Command Prompt
In Advanced Options, open Command Prompt and run: sfc /scannow. This scans for corrupted system files and replaces them. It can take 10 to 20 minutes.
Run DISM if SFC finds issues
If SFC reports corruption it could not fix, run: DISM /Online /Cleanup-Image /RestoreHealth. This pulls replacement files from Windows Update servers.
Check drive health
From the same Command Prompt, run: wmic diskdrive get status. If the result is anything other than OK, your drive may be failing. Back up your data immediately if you can get it to boot at all.

Windows loads normally after Startup Repair or SFC. If the drive health check returns 'Pred Fail' or an error, plan for a drive replacement soon. You can find more detail on diagnosing storage problems in our guide to hard drive failure signs.

If the PC powers on but the screen stays black even though you can hear fans running, the issue might be the display rather than the PC itself. Try a different monitor cable, a different port on the GPU, or an entirely different monitor. Also check that your monitor is set to the correct input source. It sounds obvious but this catches people out regularly. For more on this specific symptom, see our PC turns on but no display fix.

When to Call a Professional

Look, most PC won't turn on cases are sorted by the steps above. But there are situations where the honest answer is: this needs a repair shop.

If after all of the above your machine still shows absolutely no signs of life, no LEDs, no fan movement, nothing, and you have confirmed the power source is fine and the PSU tests dead, the next candidates are the motherboard or CPU. These are not user-serviceable in most cases, and diagnosing them properly requires test equipment. A failed DC jack on a laptop (the port where the charger plugs in) is another common one that looks like a dead laptop but is actually a £60 to £90 solder repair.

If your device is under warranty, contact the manufacturer before doing anything invasive. Opening the case on some laptops voids the warranty, so check first. For out-of-warranty machines, a reputable local repair shop can usually diagnose the fault for free or a small bench fee and give you a quote before doing any work.

You can also check our laptop repair cost guide to get a sense of what common hardware repairs typically cost before you commit to anything.

Preventing a PC Won't Turn On Problem

Most of these faults are preventable. Here is what actually makes a difference, in rough order of importance.

Sort your power protection first. A quality surge-protected power strip is cheap insurance against PSU and motherboard damage from spikes. Avoid daisy-chaining extension leads and do not overload a single circuit with multiple high-draw devices.

Keep it cool. Dust is the slow killer of PCs. A quick blast of compressed air through the vents every 6 months costs almost nothing and prevents thermal shutdowns. Laptops especially need this, because their cooling channels are narrow and clog up fast. Never use a laptop on carpet, a bed, or anything soft that blocks the bottom vents.

Shut down properly. Avoid hard power cuts where you can. Forced shutdowns by holding the power button can corrupt the file system and leave the BIOS in a bad power state. Use Start, Shut down unless you have no other option.

Keep Windows and firmware updated. BIOS and UEFI firmware updates from your manufacturer sometimes fix power management bugs that cause exactly this kind of fault. Check your manufacturer's support page every few months. For monitoring your system health proactively, tools like HWMonitor or CrystalDiskInfo give you early warning of temperature and drive issues before they become a crisis.

Handle hardware carefully. If you do any internal work, make sure everything is properly seated before closing the case. A RAM stick that is 90% in will work fine for weeks and then cause a no-boot fault at the worst possible moment. Ask me how I know.

PC Won't Turn On: Summary

A PC won't turn on is one of those problems that looks catastrophic but is usually fixable at home. Start with the boring stuff: check the outlet, check the cables, bypass the power strip. Do a power drain reset. Give it time to cool if it overheated. From there, re-seat the hardware, disable Fast Startup, and reset the BIOS if needed. Windows-level fixes like Startup Repair and SFC handle the cases where the hardware is fine but the OS has gone wrong. If none of that works and the machine is completely dead with a known-good power source, you are looking at a hardware failure that needs professional diagnosis. But in my experience, it rarely gets that far.