How to connect to a mac with remote login disabled?

Question

The screen broke on my power PC macbook and I am trying to determine ways that I can gain access to turn remote login on so that I can at least use it as a headless server. It appears there is no way to connect to it because remote login is disabled ( ssh connection refused, direct connect via firewire fails. I am wondering if there is a way to to boot in debug mode, or boot in a mode that allows me to control it from another mac, etc. It does have a DVI output that I can connect another monitor to, but the screen is just ablank background and I cannot figure out a way to access the dock or launch terminal in the other monitors view. I tried the cmd+opt+a+v on boot to see if that would duplicate the screens ( so that the main screen would be shown on the attached monitor, and therefore I could use it) but it did not appear to do anything. Does anyone have any ideas besides loading it with an image that has remote login enabled?

Answer 1

If you hold the Fn key and hit F7 while the external monitor is plugged in it should cycle through the display modes, one being that the external monitor will be the primary (or at least a mirror of the internal display). That should let you do whatever you want with it.

Answer 2

1. Hold down commands while booting to boot in single-user mode.
2. Wait for the hard drive to stop grinding, so you know you've got a command line, then type in the command shown below to enable Remote Desktop -- this will be tricky because you can't see what you type. Good luck. =)
3. After you hit return, you'll have to enter your administrator password and hit return again.
4. Type reboot and return, wait for the system to load completely and hopefully you can then log in remotely.

sudo /System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Resources/kickstart -activate -configure -access -on -clientopts -setvnclegacy -vnclegacy yes -clientopts -setvncpw -vncpw mypasswd -restart -agent -privs -all

(note: technically, I don't think sudo is necessary in single-user mode, but it doesn't hurt.)

Answer 3

1. Hold down the T key while you boot to set your Mac into Firewire Target Disk Mode. Now plug it into another computer and it should appear as a disk. You have full access to read and write anything on this disk.
2. Now, post a new question on SuperUser.com or Apple.StackExchange.com where you ask how to edit a config file (no GUI) to turn on SSH and remote desktop.

Hint: To turn on Remote Desktop from the command line, you would type this:

cd /Library/Preferences
echo -n enabled > com.apple.ScreenSharing.launchd

Note: Those commands are for the computer your are logged in on. You might need to cd /Volumes/TargetDisk/Library/Preferences in order for this to have the desired effect in your situation.

Now, eject your damaged Mac, Reboot, and you should be able to connect to it with VNC, and turn on SSH via the GUI, assuming you couldn't find the commands to enable SSH while it was attached as a disk to the other computer.

Answer 4

When you say "direct connect via firewire fails", what did you try? The simplest thing to try is to boot it in target disk mode (hold t while turning it on), plug it into another computer, and see if the HD mounts on that other computer. If you have another Mac (that's compatible with the OS on that HD), you can boot it from the target-mode drive, and then edit settings to your heart's content. If not, you can mount it as a regular HD and edit settings, etc manually.

If that doesn't work, here's a variant of ghoppe's answer to enable SSH instead of VNC (that requires less blind typing):

1. Hold commands while booting to get into single-user mode.

2. Wait for activity to stop, then enter the commands:

   mount -uw /
   launchctl load -w /System/Library/LaunchDaemons/ssh.plist
   reboot
   

3. After it finishes rebooting, SSH in from another computer. OS X advertises its SSH service over Bonjour, so if you don't know the computer's IP address, you may still be able to find it that supports that (e.g. OS X Terminal's "New Remote Connection" menu option).