# Late 2011 iMac wont boot after Mavericks install

I am not very tech savvy so please answer in lamans terms.

I recently updated my iMac to Mavericks via App Store. Few days later I was using iTunes and system kept playing up. Following day I couldn't get past the boot screen.

• Tried recovery mode. Checked and reapired permission etc. Was saying a bunch of file routes could not be recognised but said repaired fine. Next try, same info displayed.

• Tried reinstalling Mavericks but no luck. In fact on a couple of occasions it wouldn't let me do that, just kept saying try again.

• Then did internet recover and tried to revert back to Lion but wouldn't allow it cos Mavericks is on system.

Now instead of Apple grey screen on load up I get the logo and some text comes up with a bunch of numbers and says something about "panic".

I do not have any of my OS on time machine as far as I am aware. Really would prefer not to erase my HD cos then it means losing a bunch of programmes. And dont yet have photos and that backed up onto Ext HD.

There are 3 more start ups you can try:

1. Press Option-Command-P-R until you hear startup sound a second time.

2. Press Command-V during startup. -Start up in Verbose mode.

3. Press Command-S during startup. -Start up in Single-User mode.

here is more detailed information what to do.

Start up your computer in single-user mode to reach the command line. Note: If necessary, perform a forced restart as described in the Emergency Troubleshooting Handbook that came with your computer. On desktop computers, you can do this by pressing the reset/interrupt button (if there is one) or holding down the power button for several seconds. On portable computers, simultaneously press the Command-Control-power keys. If your portable computer doesn't restart with this method, you may need to reset the Power Manager.

At the command-line prompt type:

/sbin/fsck -fy

• Press Return. fsck will go through five "phases" and then return information about your disk's use and fragmentation. Once it finishes, it'll display this message if no issue is found:

** The volume (name_of_volume) appears to be OK

• If fsck found issues and has altered, repaired, or fixed anything, it will display this message:

***** FILE SYSTEM WAS MODIFIED *****


Important: If this message appears, repeat the fsck command you typed in step 2 until fsck tells you that your volume appears to be OK (first-pass repairs may uncover additional issues, so this is a normal thing to do).

When fsck reports that your volume is OK, type reboot at the prompt and then press Return.