Computer power and startup

What should you do when a computer will not turn on?

Safe first checks for a Windows PC or Mac that will not power on, shows a blank screen, or stops before the normal desktop appears.

Updated

A computer that looks completely off is different from one that has power but cannot finish starting. Before changing settings or attempting recovery, look and listen for simple signs such as lights, fan noise, a startup sound, a charging symbol, or a message on the screen.

Stop first if the device may be unsafe

Unplug the computer and stop using it if there is smoke, a burning smell, liquid inside the device, sparks, unusual heat, or a swollen battery or case. Do not press on a swollen laptop or keep trying different chargers.

After a spill, leaving the computer off is safer than repeatedly testing it. If important files are involved, mention that before anyone attempts repair or recovery.

Check the source of power

Make sure the power cable or charger is connected securely to the computer and to a working outlet. If a power strip is involved, check that it is switched on. For a desktop computer, confirm that the monitor has its own power and that its cable is connected.

Use the charger intended for the computer when possible. A connector that fits does not always provide the power the device needs. Look for damage, looseness, or a charging message before borrowing another adapter.

  • Try a known working outlet without moving other equipment unnecessarily
  • Check the charger, cable, and connector for visible damage
  • Disconnect unneeded USB devices, docks, printers, and external drives
  • Note whether any light or sound appears when power is pressed

Decide whether the screen or the computer is off

A computer may be running even when the display is blank. Listen for the fan or startup sound and look for keyboard, charging, or power lights. On a desktop, check that the monitor is on and set to the correct input.

If the screen shows a logo, question mark, error, spinning symbol, or recovery message, the computer has turned on. Take a photo of the exact screen and avoid choosing erase, reset, reinstall, or recovery options until you understand what they will do to files and programs.

Avoid repeated forced restarts

One normal restart or manufacturer-recommended power check may help, but repeating forced shutdowns can interrupt updates or make a storage problem harder to assess. Stop if the computer returns to the same error or never reaches the normal sign-in screen.

The next step may involve the charger, battery, screen, internal power hardware, storage, or startup software. The exact signs you observed help narrow that choice without guessing or buying parts first.

Questions about this problem

Use these answers as a starting point, not a diagnosis.

Why do I hear the fan when the screen is black?
The computer may have power while the display, cable, graphics output, or startup process has a problem. Note every light, sound, and message before changing display or recovery settings.
Should I keep holding the power button?
A manufacturer may recommend one specific power-button check, but repeated forced shutdowns are not a general repair. Stop when the same symptom returns or an update or recovery message appears.
Will checking the computer erase my files?
Basic observation and power checks do not erase files. Resetting, reinstalling, erasing, or replacing storage can affect files, so discuss important data and backups before those steps are taken.

Computer still not starting?

Call with the computer model, what happens when you press power, and whether important files need to be protected before the next step.