Mac Troubleshooting

Posted by wojtek on April 25, 2015 in Default

My private Mac Book Pro was affected with last post update issue. It’s 15” Late 2011 so in grup affected with some video issues. So one day it just stucked on boot screen. But it’s a good opportunity to refresh knowledge about Mac hidden opptions and command line tools. Without unnecessary long introduction I’ll just list them.

Boot Options

Startup Manager

Press and hold Option key while booting. Instead of logging screen you’ll see Startup Manager showing options to boot with. In addition pressing and holding C will boot directly from CD/DVD drive and N for network boot.

Apple Diagnostics

Simply press and hold D key while booting.

Safe Boot

Could be known as Safe Mode. This is minimal load, all third party stuff will be disabled and only necessary kernel extensions will be loaded. This could be really helpful in some cases. Just press and hold Shift just after booting sound.

Single-User Mode

Are you command line ninja? Then this mode is for you. Command line you will get after pressing and holding Command + S while booting.

Verbose Mode

To check hidden system messages while booting, hold and press Command + V on startup.

Reset PRAM

PRAM stores some important information. But usually is the first and the simplest way to troubleshoot your Mac. So press and hold Command + Option + P + R. Yes it’s probably one of the most difficult keyboard shortcuts but sometimes you need to put that efford.

Recovery Mode

Probably the last thing you want to do but still good to know how to do is running recovery mode. Also simple command press and hold Command + R.

Command Line Tools

If you enter command line you probably want to take some actions there. Here are some useful commands:


To run system updates in command line use:

sudo softwareupdate -i -a

Enabling WiFi

To enable

networksetup -setairportpower en0 on

and just in case to disable

networksetup -setairportpower en0 off

to join WiFi network

networksetup -setairportnetwork en0 WIFI_SSID WIFI_PASSWORD

to add DNS

sudo networksetup -setdnsservers "AirPort"

and to list network interfaces

networksetup -listallhardwareports



For more options just use man works like in Linux ;)

Credit: image

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