OS X Yosemite keeps rebooting on start up

I'm having this same problem. I have an Early 2008 MacPro using 10.10.1.

The problem didn't start (for me anyway) until the last OS update. For a few days now, it reboots in an endless cycle whenever I first start it up in the morning. The problem persists until I completely power it down and then sometimes it will boot properly. Before this restart problem began I noticed some unusual behavior, right after the OS update. What would happen then was: when I shut down it would often start up again on it's own. I'd sit here and watch it shut completely down, and then start right back up. I began just manually powering it off instead of using the Shut Down menu.

You know how when you do an OS update you often have to let it reboot for it to finish installing? It almost seems like maybe there is something leftover from the update script where it's still trying to install part of the update that requires a restart. Just a guess.

I know it has nothing to do with a bad hard drive or a graphic card, since I'm using the afflicted MacPro right now and I replaced the boot drive just a couple months ago. Also I'm using a newer graphics card and I discovered some time ago that the firmware won't work with this card - so I know the graphics drivers must be loading for my card because I do see a bit of the startup screen before the machine restarts again.

All - sorry to see you have had this issue. I have had the exact same problem with my late 2011 MBP (i7, 8 GB's RAM, running 10.10). Firstly below I'll write my solution and then a description of all the symptoms my problem had shown for comparison to yours (petty identical though!)

SOLUTION -

This is painful and time consuming but if you have a Time Machine back-up this could solve it. In short - reformat your start up drive through the Disk Utility and do a complete re-install of OSX (mine allowed a reinstall of 10.9 and then from there I could update to 10.10). From there you can begin the long process of reinstalling your applications either via the App Store or via physical media you may have (you can't drag and drop them over from a back-up) and restoring your personal documents, folders and files (such as iTunes music and iPhoto pictures) by dragging and dropping from the time machine back-up into the relevant Home folder on your reformatted Mac.

Trust me, this was a last resort and I really did not want to do this but (as your see from the description below) I had no choice and (most importantly) IT WORKS! So far my MBP has been up and running for 24 hours with no shutting down, slowing down or graphical artefacts of any sort.

DESCRIPTION OF ISSUES -

Starting about 12 months ago when running 10.9 I noticed There would often be graphical artefacts on start-up and every now and again the MBP would restart randomly (when on battery power usually at about 60% for some reason). I took it into my local re-seller who I got it from who did a full diagnostic and said there were no issues either with hardware or the battery. I then later took it Ito an Apple Store and a Genius said the same - no hardware issues at all.

6 Months later the problem got worse and after updating to 10.10 my MBP slowed to a crawl and more frequently turned off at random. I repaired permissions and verified the disk using Disk Utility (all fine) but a few days ago it became apparent it wouldnt stay on for more than 5 minutes at a time. Then it had a complete meltdown.

it wouldn't get passed the start-up screen 9/10 times and when it did an error stating 'A Graphics Error has been detected' and would restart after about 2 minutes. I managed to get into there diagnostic screen and ran a full report - no hardware issues Thank God. The MBP would not boot into Safe Mode but I could control + V at start up to see the boot log and it was clear there were errors causing what I can only assume was a kernel panic killing start up.

biting the bullet I decided to reformat using the Recover Disk (Options key at start-up) which allowed me to get to Disk Utility and implement my solution above. Incidentally the first 5 attempts at this resulted in a soul destroying Blue Screen but it did finally work. All I can suggest if this is happening to you (as some have reported) is to keep trying and hopefully you'll get lucky as I did.

As the solution above states this worked and so far so good - Diagnostic Test confirms no hardware issues and Disk Utility reports all fine (although advised to run a test of disk permissions straight after re-install of the OS).

Good luck with this issue. If it comes to it a full restore like I did might save your comp and sanity. For those running older machines maybe just sticking to 10.9 would be the safest choice once you have gone back to scratch.

Thanks for sharing your problem because I also have the exact same problem and I think worst. I can't boost into anything. When I go into my mac it kept restarting. Go into my Window boot camp every thing turns black. When I go into the recovery there is a hope of the apple and a loading ring appear up and when it disappear every turn to blue. I try to cmd+r and boost again the glitch screen is still on and I still can't go in. Please HELP!!!!!! I JUST NEED TO ENTER AND DRAG ALL MY DATA INTO A HDD AND clean everything. Please help list any method or ways to help me please!!

Just wanted to add that I was able to get my 2008 MacPro working again. I didn't have a recovery partition on my HD, so I ended up using a Snow Leopard DVD to reinstall the OS, and then I recovered all I could from my Time Machine backup. All in all it wasn't too painful, took maybe a day to get everything back to the way I like it. I then updated to Yosemite - although I did consider just sticking with Snow Leopard.

Since I've reinstalled everything worked fine for a couple of weeks, but just in the last few days my MacPro has started rebooting again on powerup. Now it does start up successfully, but it always reboots once during powerup. I wouldn't rule out some kind of hardware issue, except that it worked fine for a while after the Yosemite reinstall - about the same amount of time as it took after my original Yosemite install before it started having problems.

System-wise, I have a fresh system HD from last year, and during my MacPro downtime I took the opportunity to completely disassemble and clean out dust buildup, which included reseating all connectors and testing the memory. The only thing I've noted which is unusual for my system is I replaced the stock video card because I wanted something faster, and when I replaced the system drive last year I noted that the firmware does not work with my new card (which is over a year old now). I had to replace the stock video card to be able to see the system set up when I replaced the drive. However, I've never received any kind of error or anything indicating a graphics card issue like some posters have mentioned.

Just wanted to chime in here with a suggestion. I was having unexpected system restarts in Yosemite on an Early 2011 15" MBP. I read that disabling file vault (which was enabled when I upgraded to Yosemite) might help, so I disabled it. Since then, I've not had a reoccurance of the restarting/logging out problem. I hope this might help someone with the same problem!

I was experiencing the same thing, but with a brand new MacBook Pro Retina 13".

I gave the following a try and so far no restarts, but I haven't fully tested it over a few days yet:

https://www.afp548.com/2015/01/14/when-yosemite-has-fallen-and-it-cant-get-up/

Thought I'd post in case it helps anyone else.

I have a 2007 Mac Mini and I am currently running Yosemite and have been running it for several months now with NO problem whatsoever EXCEPT that when I turn it off (which is once every 2 weeks or so - been doing that since 2007 by the way) it will reload before starting up. Not sure why but I have no other issues at all besides that.

Thoughts?

Maybe this might help some MBP users who qualify-

http://www.macgasm.net/2015/02/19/new-apple-repair-program-addresses-2011-2013-m acbook-pro-video-problems/

Same issue here, for the second time 😟. I guess I could reformat and start over from backup. That sounds pretty scary.

I have a mid-2010 15" MacBook Pro. The graphics card went out about a year ago. I was getting all kinds of cool designs on my monitor and random reboots when I plugged in the power cord. Apple replaced the whole board, no charge. That was a year ago.

It is happening again now.

It took me forever to install Mavericks. I was leery. Everything I read said Mavericks messes with Seagate external drives. I use SuperDuper for backups. I started using CrashPlan just in case. I guess I could go through the painful process of reformatting. Was it a permanent fix?

Any other ideas, guys? Any easy fixes, I hope?

Hey Jasmine, have you tried disabling FileVault? If it is enabled that is. Disabling it fixed the problem for me.

Otherwise, I recommend the repair program RosscoB mentioned in the post before yours.

Thanks, Sun. I wish I could do that but I never used FileVault. I always turn stuff like that off if I know about it.

DId anyone ever REALLY solve this? This just happened to me, too. MBP 15" late-2011. Reboots and reboots in endless cycles, and none of the start-up options work, NONE!

It started with graphics problems - lines, split screen, freezes - a day or two ago. Now I can't even get it into safe mode or recovery...

I don't want to spend hours on Apple Support. I have seen at least two dozen posts about this very problem all over the internet. Clean reinstall can't be the solution. That's why I left the Microsoft world years ago!

Any news, and does anyone from Apple ever read or care about these posts? Any help highly appreciated. I am stuck and need this for work...

thx in advance

Christian

My MacBook Pro (late 2012) started doing weird things shortly after upgrading to Yosemite and enabling FileVault.

Initially it would boot as normal but it would take several attempts to get it to take my password even though I typed it correctly every time. It was like the keyboard was not responding except that the password field was registering the characters I was typing for my password, so I knew it wasn't a keyboard issue and also because once I got logged in the keyboard was fine.

Next it started kinda of booting in REVERSE! Upon power up, the login screen would come up immediately (this was after a complete shutdown, not a sleep. I only and always do complete shutdowns). Then once I got the password to finally "take", the screen would go completely black and go through a complete reboot with the progress line going across the screen which then lead back to the logon screen again where I would logon AGAIN. This might repeat at least another 2 times before I would get to the desktop and be able to use the Mac.

Somewhere in this conversation chain I read TURN OFF FILEVAULT.

SO I DID. That's the only thing I did and now everything is working as it should. The machine boots (from a complete shutdown) as it should and I only have to type my password ONCE and it takes it. It also runs faster and is more reliable.

COME ON APPLE STOP PUTTING LANDMINES IN YOUR SOFTWARE RELEASES!! FileVault looks like something I could use. Please fix this.

Yours,

BuddBBird

Christian

See my reply under buddobbird. I fixed this problem on my MacBook Pro.

Hi, and thanks. I have never had File Vault turned on, so that can't be the cause of the problem.

I have subsequently decided to do a clean reinstall of OS X but it seems that it is still somewhat unstable. I will go to a store to run a full diagnostics if it keeps playing up.

Rgds

C