how can I restart my 2009 iMac

danielfromstone lake wrote:

My older iMac won't start up. The Apple symbol appears along with the status bar, then when it gets about 3/4 loaded it just goes black. I understand it might be dying but I need to access all the data so I can migrate it to my wife's newer iMac

After trying all the steps in the link provided by dialabrain, if you still can't get it to start, keep in mind that there are many reasons a 2009 iMac can fail to start up, one of which is internal drive failure. So you could then take it to a third party Apple Authorized Service Provider (AASP) -- you can find them on the Apple site in the Support area. Many of those independent authorized Apple centers are still willing to work with obsolete Macs like yours. You could ask them to try to boot the Mac from an external drive and then see if the data can be recovered from the internal drive; you can also, if that does not work, ask them to remove the internal drive, place it in an enclosure, and then try to access the data from it. Should all these steps fail, you would need to then consider use of a drive recovery service, which could be $hundreds to $thousands, but has a better chance of succeeding with a mechanical (spinning) drive (versus an SSD), I think you probably have a mechanical drive.

A Mac that is 15 years old should be backed up every day if not hourly because all electronic and mechanical devices eventually do fail, it's a matter of when not if. iCloud or other cloud services (Dropbox, Google, Microsoft) is another approach to protecting against computer failures. External backup drives can be obtained for as little as $50 and Apple's backup software is included with the OS and free. If you don't have such a backup and none of the above works out, you will at least know that you have tried everything.

I use newer Macs for important things, but also have around the house 2011 and 2013 MacBook Airs, and a 2015 iMac. I treat these like they could fail anytime, which they could. We used to have a 2008 iMac but it failed last year when it stopped starting up (power supply failure). iMacs like laptops are vulnerable to thermal problems because everything is packed into a very tiny space and thermal cycling is one very common cause of electronic circuits/components wearing out. As many thermal variations are experienced, the solder joints contract and expand slightly with each one and eventually crack or fail. 15 years is a VERY long life for any computer, much longer than average. The key is backups, Time Machine or other. With good backups, one can transfer everything to a new computer when the old one fails and continue where you left off.

If you're unable to boot up your 2009 iMac see if you can boot it into Target Disk Mode.

If you can you can connect it to your wife's iMac with the appropriate cables and use the 2009 iMac as an external hard drive for copying the necessary files from it.

If your Mac starts up to an Apple logo or progress bar - Apple Support

I suggest that you stop trying to start it up. Yes, it is an olde computer and likely the HD is failing. Trying to restart puts additional work on the already failing hard drive. Do you have a Time Machine backup? If not, you may be out of luck.