Boot-Up Problem

Since I installed the last Yosimite update (Version 10.10.5), my iMac will not boot up. When it starts, the boot screen (Apple logo) and a progress bar appears. The progress bar fills up until its about 2/3 full then nothing happens. I have let it site for days to see if it will finish booting and nothing happens. I have also tried the boot-up shortcut keys and nothing happens. Can anyone tell me why this is happening? Will I need to upgrade my CPU?

Welcome to the forum.

You can't upgrade the CPU in an iMac. What iMac do you have? (That may be hard to find out if it won't boot, unless you already know what it reported in About This Mac). Have you tried booting into safe mode? (Yes, you mentioned the shortcut keys, but it's worth asking.) BTW, you need to HOLD DOWN the keys when booting, not just tap them. Where did you get the update to Yosemite? Do you know how full the hard drive was before the problem? We'll need a bit more information before we can try to get it going again.

The iMac I have is the Model A1224 / Mid 2007 and Early 2008 / 2.0 or 2.4 GHz Core 2 Duo processor, i can't remember which. I have tried booting in safe mode, but it doesn't do anything, just stays on the boot screen. I downloaded the Yosemite update from the Apple App Store. The hard drive isn't close to full, I have a 3TB hard drive in it and it might be about half full, at most. I had a similar problem last fall after I installed the update. I was able to start-up my computer but it rain painfully slow. I would click on anything (app, folder, etc.) and the "beach ball" load icon would appear. Folders or apps would take at least 5 minutes to open. I then reformatted the hard drive and it ran fine until I updated to the latest version of Yosemite again.

Have a read of this link from Apple Discussions which advice 2TB is the limit for your machine and it may be you have reached that capacity. Click on 'More FReplies' at the foot of the page to access page 2:-


https://discussions.apple.com/thread/2639300?tstart=0

Thanks harryb2448. Would the limit be 2TB of data or the capacity of the hard drive...I replaced the hard drive a few years ago and there was more on it then, then there is now and it ran with no issues until I updated the OS. That update could have put my hard drive over 2TB, I am not sure how much was on there then. Also, if that's the case, will I still be able to retrieve the data on that hard drive?

I almost hate to ask, but do you have a backup, either Time Machine, cloud based (iCloud Drop Box etc.) or a clone? If not you may have a problem retrieving your data.
As your Hard Drive won't boot and I'm assuming you have tried holding down the command and R keys to boot into Recovery mode (if not try it). To run any diagnostics or repair you will need to boot from an external source e.g. a bootable clone if you have one. If not then it's off to the Apple Store I'm afraid.
Once booted from another source the HD may be repairable but if not then you are looking at a replacement HD and a backup of some sort will be required to restore your data.

I have some items backed up, but unfortunately, not everything I would like to recover. I have tried to boot into Recovery mode with no success.

I'm sorry, gtaylor6, it doesn't look good with respect to your HDD.

As I understand things: can't boot in normal way; can't boot into Safe Mode; can't boot into Disk recovery.

One further option: you might try booting into Internet Recovery which is - Cmd + Option + R. When you start the reboot from the switched off position, hold down these keys as soon as you hear the first chime and keep holding down till you see the picture of a world map/globe. Then release the keys.

If this works, be patient. It can take a while. Needless to say, you must be connected to the Internet. A direct physical connection, if possible, is better than WiFi.

Ian

I will try booting into Internet Recovery, thanks.

Do you have the original disc for that model iMac, o even the Snow Leopard disc?

I do, yes. If I boot from the disc, will I lose all the data on the HD?

Not at all. Pop the disc in, reboot and hold down 'C' and run Repair Disk to see the state of the driver. From the link provided your machine will only be able to use 2TB. What is on it that takes up so much room? They might conceivably go onto an external hard drive. This explains it in full. DO not erase the drive:-


https://grok.lsu.edu/article.aspx?articleid=9849

Whether you will or will not lose data will depend upon what else needs to be done. When you boot from the DVD open Disk Utility and run Disk First Aid. If errors are reported, Let Disk Utility attempt to make the repairs. That usually does not lead to data loss. If you have to format the drive that will lead to data loss.

If you can boot from the DVD and get it to "see" the hard drive it might be a good idea to make a backup. That may however push the drive over the edge and cause it to finish failing.

It was my assumption that as gtaylor6 was running Lion then may be unable to boot using the Snow Leopard disks. Still worth a try I suppose but there Disk First Aid will be part of Disk Utility in Snow Leopard but it may balk at repairing or even diagnosing Lion. It might allow reinstallation of Snow Leopard but that will erase the disk.
Either way gtaylor6 let us know what happens and good luck.

The problem Rod is the machine will not boot at all so Recovery Mode is out. He is running Yosemite and I guess trying Snow Leopard DVD is a last resort. It is the original DVD so it should work (I trust).

Sorry dont know where I got Lion from, too many posts at once.

harryb2448 said:

The problem Rod is the machine will not boot at all so Recovery Mode is out. He is running Yosemite and I guess trying Snow Leopard DVD is a last resort. It is the original DVD so it should work (I trust).

Click to expand...

Agree, Harry. That is why I suggested Internet Recovery (Cmd + Opt + R). As I understood it, Recovery Mode depends on an intact Recovery Partition on the HDD whereas Internet Recovery only requires an internet connection and a great deal of patience as the Mac communicates with the Apple Servers and all actions on the Mac such as DU and re-downloading the OS are controlled from there?

Ian

I thought Internet Recovery was only available on machines that shipped without OS discs?

No from OS X.7 on and some came with USB thumb drives with OS on. Recovery Mode works on systems later than Snow Leopard.

This machine came with the OS X.6 DVD when new so worth a try. I was suggesting Recovery Mode in Yosemite if the DVD does not boot, not Internet Recovery.