Getting started Is it just the display that’s not working? Why does the screen appear garbled? The Mac started up – why is the screen staying grey? Nothing appears except weird text – what’s happened?

When your Mac won’t even power up.

Where is the power button, anyway?

A desktop Mac will have a physical power button, usually on the back, marked with the “standby” symbol, a circle broken by a line. MacBooks have a button at the top right of the keyboard; this includes Touch ID models, but to start from cold you’ll need to hold the button down, not just touch it.

What if the Mac shows signs of life but the screen stays dark? If it’s a separate monitor, unplug, reconnect and swap its cables. Check built-in menu options, such as input selection. If you haven’t used it before, look online for info on compatibility; even if the manufacturer recommends it, others might have discussed problems on forums. If it’s a MacBook screen and your model has no known display issues, reset the SMC.

Why won’t the power button respond?

A common reason for not being able to power up your Mac is that it’s already powered up but failing to wake from sleep. It’s similar to when macOS hangs while you’re working, usually because an app or Finder has crashed – it’s just less obvious because you can’t see what’s happening. All you need to do is hold down the power button until the power cuts out, which may be felt as a faint clunk. Wait a few seconds, then press it and let go to start back up.

This can happen with a 15-inch MacBook Pro made between 2011 and 2013 due to GPU failure resulting in a “stripey” screen. Apple no longer offers free repairs for these units, and working around the issue is tricky (see bit.ly/mlmbp2011gpu).

Does the Mac have power coming in?

So pressing a key, the mouse or trackpad button doesn’t wake up your Mac, and pressing the power button doesn’t bring the screen to life. Do you hear a chime or whir, or see any lights, or a faint glow on the screen? If not, that could mean that there’s no power. If it’s a MacBook, make sure it’s plugged in; try a different charging cable, and if possible another charger.

For a wall-powered Mac, try a different cable. You should check the wall power socket too.

This can happen when macOS detects problems and tries to clean things up, so be patient and it may eventually start normally. If not, try starting up in safe mode. No? Reset the SMC (which we’ll cover on the following pages). Still no? One possible cause is a faulty memory module, so if you’ve added any to your Mac, turn it off, remove the extra modules and try again. If it works, try again with the RAM, but you may need to replace it.

Is the battery the problem?

Yes: as MacBooks get older, the batteries hold less charge and eventually start to fail, with various symptoms – more on that later! Specific problems with the 15-inch MacBook Pro (Retina, mid– 2015) and 13-inch MacBook Pro (non-Touch Bar, from October 2016) may require urgent repair, which Apple will do for free: see bit.ly/ apple-exchrepprog. Address battery issues promptly, as lithium-ion cells are prone to catching fire if faulty.

A grey screen overlaid with blocks of scary-looking text means your Mac has suffered a kernel panic. It may be fine after you turn it off and on again. If not, restart in safe mode and update macOS. If it won’t start at all, unplug all peripherals and try again, then add back one at a time.