How to view crash log on macbook that won't boot?

[Knawlidge]

I have a macbook here that is stuck in a restart loop. It boots until it gets to the blue screen and flickers and goes back to a post screen and keeps retrying. It also displays a message that a crash log was written to file xxxxxxx.

I can boot into single user mode and found the folder containing the crash log, how do I view that file in single user mode? If I can't read it in single user mode how can I read it, transfer it onto usb and view on my imac? What program would I use to view it? And if I do have to transfer it onto usb how do I mount my thumb drive in single user mode?

Thanks in advance.

 

[Hellhammer]

Verbose mode

If you can boot in single-user mode, you should be fine, see this

 

[Sun Baked]

Can try a safe boot, by holding down the shift key.

This will stop it from loading a bunch of stuff, so if a login item or something else is hanging the boot -- it should boot. However it takes forever to boot this way.

Still should allow you to get at the OS and make changes.

Using a FW cable and using target mode is another method, should allow you access to the drive at least.

If the "/sbin/fsck -fy" is giving you a non-correctable error ... rebuilding the b-tree catalog may help which will be something like "/sbin/fsck_hfs -rd /dev/disk0s2" where diskXXX is the drive listed in the text above the you have not run fsck yet message.

If you have 3rd party ram in there, might take it out as a hail mary shot that is crashing the machine on boot.

 

[revbarabbas]

To read a log in single user mode you can use nano. Just type:

nano "filename"

 

[Knawlidge]

I have tried safe mode and it did the same startup loop. The LoginWindow is where the crash is starting according to the log file name.

I have ran fsck and it has repaired everything with no errors showing now.

No 3rd party ram.

Going to try nano to take a look at the log now.

Thanks for the tips everyone!

I'll post back after I get a look at the log(have to head out so it might be a few hours)

 

[Knawlidge]

Thanks Matthew the nano command worked and I was able to view the crash log.

The owner ended up deciding to have me wipe it and install snow leopard, so I never got to the bottom of the problem.

Thanks for all the help.

 

[Hellhammer]

Thanks Matthew the nano command worked and I was able to view the crash log.

The owner ended up deciding to have me wipe it and install snow leopard, so I never got to the bottom of the problem.

Thanks for all the help.

It was likely some corrupted system file blocking the boot. Nothing to worry about if it work now