MacBook Pro boot up error

[dsiim]

Hi

My 2011 MacBook Pro won’t boot. When I push the power button, I hear the hdd turn on, but then shortly after a light pitch sound, and then it shuts down again. No input on the screen, just black.

Power cord is connected, and shows power.

Is it a hdd failure, or a battery failure?

 

[john991]

Hi

My 2011 MacBook Pro won’t boot. When I push the power button, I hear the hdd turn on, but then shortly after a light pitch sound, and then it shuts down again. No input on the screen, just black.

Power cord is connected, and shows power.

Is it a hdd failure, or a battery failure?

Try this

Start the system in Safe Boot mode

1. Restart the Macintosh. Press and hold the Shift key immediately after you hear the startup tone.
2. Release the Shift key when the Apple logo appears. Safe Boot appears on the Mac OS X startup screen.

My MacBook Pro 2011 continuously reboots on start up. I replaced the hard drive, reinstalled the macOS to have the same issue. So on mine it’s either the OS or a hardware failure.

 

[dsiim]

Try this

Start the system in Safe Boot mode

1. Restart the Macintosh. Press and hold the Shift key immediately after you hear the startup tone.
2. Release the Shift key when the Apple logo appears. Safe Boot appears on the Mac OS X startup screen.

My MacBook Pro 2011 continuously reboots on start up. I replaced the hard drive, reinstalled the macOS to have the same issue. So on mine it’s either the OS or a hardware failure.

Thanks. However, it won’t even go to the startup tone. When I turn it on, it makes a high pitch sound from inside the MacBook then immediately turns off again. All the keys seems to have no impact, as the MacBook only have 3-4 seconds before it turns off again.

 

[Audit13]

Disconnect battery, connect charger, wait about minute, see if the machine turns itself on and is useable.

 

[Fishrrman]

You could also try connecting a bootable external drive, or perhaps the original install DVDs (if you still have them).
Or... a USB flashdrive with a copy of the OS installer on it.