Troubleshooting

PC Won't Turn On? A Step-by-Step Checklist

Last updated November 6, 2026 · By the PC Guide Info editorial team

When a computer will not start, the cause is often simple. Work through these checks in order.

1. Check the power supply

Confirm the power cable is firmly connected at both ends.
Try a different wall outlet or extension lead.
On a desktop, make sure the switch on the back of the power supply is set to on.

2. For laptops

Connect the charger and look for a charging light.
Hold the power button for about 30 seconds to release stored power, then try again.
If possible, test with a different compatible charger.

3. Check the display

Sometimes the computer is on but the screen is not showing anything. Check the monitor cable and power, and try another cable or input.

4. Remove external devices

Unplug USB drives, printers and other accessories. Occasionally a faulty device can stop the computer from starting.

5. Listen and look

Do the fans spin?
Are there lights on the motherboard or case?
Does the computer beep? Beep patterns can indicate memory or graphics problems. Check your motherboard manual.

6. Reseat memory and cables (desktops)

With the power off and unplugged, press the memory modules firmly into their slots and check the power connectors to the motherboard. Touch the metal case first to discharge static.

7. Consider the likely causes

A failed power supply.
A faulty power button or case connector.
Failed memory or motherboard.
On laptops, a drained or failed battery or a faulty charging port.

When to get help

If you have tried these steps and there are still no signs of life, take the computer to a qualified repair service. Do not open a power supply, because it can hold dangerous voltage even when unplugged. If you have important data inside, a technician can often recover it.

This article is for general information only and is not professional advice. Features, prices and menu names may change between software versions. See our disclaimer.