When I switch on my MacBook Pro 2011, I see the Apple logo with progress bar but before it enters the next screen it turns off. Why?
Troubleshooting is a process of elimination and can take quite some time. This means trying various things and reporting back with the results in order to try and get to the bottom of your problem.
Apple Hardware Test / Apple Diagnostics
The first thing to try is running Apple's built-in hardware diagnostics. To do this:
- Ensure your MacBook Pro is connected to AC power
- Start your computer
- Immediately press and hold down the D key before the grey screen appear
- When the icon appears on the screen let go of the D key
- Select your language and click the right arrow
- Select the "Perform extended testing" checkbox
- Click the Test button
- Take a note of the results that appear in the bottom-right window
Report back with your results.
NOTE: If holding down the D key doesn't work, you can also try holding down the OptionD keys during startup to try and run the diagnostics test via the internet.