Computer Won't Start? Troubleshooting Guide

A computer that won't start is one of the most stressful tech problems you can face, especially when you need to get work done or access important files. The good news is that it's often something simple, and you might be able to fix it yourself without any technical knowledge.

Before you panic or assume the worst, there are a few straightforward checks you can do. This guide walks you through them in order, from the most common culprits to less obvious issues.

Check the power and cables first

This sounds obvious, but you'd be surprised how often a computer won't start simply because it's not plugged in properly. Check that the power cable is firmly connected to both the computer and the wall socket. If it's a laptop, make sure the charger is plugged in and the cable isn't damaged.

If you're using a power strip or extension lead, try plugging the computer directly into the wall socket instead. Power strips can fail silently, leaving you thinking your computer is broken when actually the strip just needs replacing. Look for indicator lights on the power strip to confirm it has power.

Practical tip: If you have a lamp or phone charger nearby, try plugging that into the same socket to confirm the outlet actually works.

Press the power button and wait

Hold down the power button for a full 10 seconds. Some computers take longer to respond than you'd expect, especially older machines or ones that have been shut down for a while. After 10 seconds, release and wait another 30 seconds to see if anything happens.

If you see lights come on inside the computer, or hear the fan spinning, then something is happening. Your computer might be starting up, it's just taking longer than usual. Leave it for another minute or two before trying anything else.

Practical tip: Don't keep pressing the button repeatedly. One long press is better than lots of short taps, as multiple presses can sometimes trigger a hard shutdown in the middle of startup.

Look for lights, fans and sounds

While you're waiting, pay attention to what's actually happening. Is there a light on the computer case or monitor? Are you hearing the cooling fan spin up? Can you see any lights on the keyboard? These all suggest the computer has power and something is running.

If there's absolutely no sign of life, no lights and no sounds at all, then it's likely a power issue. But if you can see or hear signs of activity, the computer is actually working but something else is preventing it from starting up properly. This is less serious than total power failure.

Practical tip: Many computers have a small LED light on the case that shows power is connected. On a Mac, look for a light near the power port. On a Windows machine, there's usually a light on the front of the tower.

Check your monitor is switched on

Here's another surprisingly common one. If you've got a separate monitor, it needs its own power and its own on switch. The computer might be starting up perfectly fine, but if the monitor is off, you'll see nothing on screen. Check that the monitor's power cable is plugged in and the monitor itself is switched on.

Also check that the cable connecting the monitor to the computer is firmly plugged in at both ends. Sometimes these connections work loose, especially if you've been moving things around your desk. With a loose connection, you'll get no picture even though the computer is running fine.

Practical tip: If you've got a monitor you can borrow from somewhere else, try plugging that in temporarily. If that monitor works fine, you know the issue is with your original monitor, not your computer.

Try a hard reset

If your computer has power but won't respond to the power button, try a hard reset. Unplug the power cable completely, wait for 30 seconds, then plug it back in and press the power button again. This clears any stuck processes and gives the computer a fresh start.

For laptops, you might need to hold the power button down for 10 seconds while it's unplugged. This discharges any remaining power in the system. Then plug it back in and try starting normally. Some laptops also have a small reset button near the power port, though this is less common these days.

Practical tip: If this works, great. But if it doesn't, don't keep repeating this step. Move on to the next checks instead.

Look for error messages or startup screens

Sometimes a computer will try to start but get stuck on a startup screen, error message, or blank screen. You might see something like 'No bootable device found' or 'Windows startup repair' or just a black screen with a cursor. These messages tell you what's actually wrong, rather than the computer failing silently.

Write down exactly what message you're seeing, as this is really helpful information. If you're seeing an actual error message, the computer is at least trying to start. The issue is something specific that's preventing it from loading fully, which is often fixable.

Practical tip: If you see a startup repair option, let it run. Windows sometimes finds and fixes its own issues this way. But don't let it run in an endless loop. If the same message keeps appearing, that's a sign it needs professional attention.

Know when to get help

If you've tried all these steps and your computer still won't start, there's likely a hardware issue like a failed power supply, motherboard problem, or hard drive failure. These aren't things you can safely fix yourself, and trying to force it might make things worse.

The earlier you get help with a computer that won't start, the better your chances of recovering any data that's on it. A computer left unpowered for weeks is less likely to start than one that's troubleshot immediately. Whether you're in Stockbridge, Morningside, Leith or anywhere else in Edinburgh, don't wait and hope it sorts itself out.

If you've worked through these steps and your computer still won't start, give Rob a call on 07352 385477 or email rob@curly-it.co.uk. He handles computer repairs and diagnostics right here in Edinburgh and can also help remotely if you're anywhere else in the UK. With a no-fix-no-fee approach, there's no risk in getting it checked out properly.