IMAC powers down before boot up is complete

After a forced power down my iMAC won't boot again.
The machine simply powers off after the spinning gear on the gray start up screen spins for a few seconds.
I've tried booting in safe mode, doing a PRAM reset and inserting the Installer DVD but I don't even get to any of these steps and the machine turns off.
help!

Do the SMC reset at least 2X, sometimes it doesn't always work the first time. If you still don't have luck please restart in Safe Mode , this will clear some caches. If that doesn't work you may have a hardware issue and should then try running Apple Hardware TestHardware Test in Extended Mode. If you can run AHT in Extended Mode if it does not find errors after the first pass then run it again 2-3 more times, sometimes AHT doesn't find errors after the first or second pass.
If you still don't have any luck then your can try to boot from the Leopard Disc by holding down the C key when you hear the startup tone. This is a slow boot because loading from the DVD is time consuming. Then enter Disk Utility (Applications - Utilities - Disk Utility) and Repair Disk Permissions and also run Repair Disk. If the disk return errors continue to run RD at least another 2-3 more times until no errors come up. However your computer is old and the HD may have failed.

Similar Messages

IMAC Powers Down by itself, When it reboots only the Spot Light visable

Hi,
Hope someone can help, we have two Imac 20' G5 2ghz with 1.5gb Ram. Both system are crashing with the same problem.
The IMAC Powers Down by itself, and when it reboots only the Spot Light Field is viable, Only way to recover it is to rebuild OS. Sent the System back, and Both Logic board and Hardrive were replaced, and the day system crashed again did they same thing. We also have 2 Imac 20' G5 Isight Models working in the same envioroment and are not experiencing any problems with those systems. Any Ideas?

Sounds to me like you may have bad power supply units. I know of several people who had Rev B machines that were covered by THIS repair program.
Even though it says rev A machines are covered. It seems like some that were made early in the switch still used some of the components that were fingered out as not functioning properly. I would check your serial number.
Either way, give AppleCare a call, you should still be covered. And if you had some things replaced, like you said, let them know its doing same thing. Its for this reason that I have a hunch you are getting those old MBs that were having issues. Its more than the Power supply I sispect. Since you cant run it normally when it does power up, seems to me you may have several issues going wrong at the same time.
Hope you get it fixed.

Why does my iMac shut down before it can boot up After installing 7.3 update on my iMac?

After installing 7.3 last night, I hit restart and went to bed. My intel iMac i7 3.4ghz was powered down this morning, and only after unplugging,waiting, rep plugging,
It finally powered on, only to boot to the gray apple screen, go black and silent. (this exact issue had me lugging it back to apple a month after purchase, today is 93 days)
Recovery mode got me about one second further in bottling up before shutting off.
I was forced to upgrade from an unproblematic pc g5, after iCloud, so do not own snow leopard and was told I would never need a re install disc.
Has anyone having the powering off during boot after updating to 7.3?

omg. I would copy and paste your original post to the iMac section. You're talking about a fine piece of equipment, the Intel iMac i7 3.4ghz , and you should not be having such problems. Maybe others in the iMac i7 community might also have some ideas.
Re: the safe boot. That's good that it worked. This is fairly new and very, very helpful with a dead computer because at least you can get to Safari, get to the Internet and get ideas and seek help.
But why did it shut off after a while? That's not right. No reason it should have done that.
From something you said I would worry about your power supply problem or this PerIphrEa. I don't know what that is but Migration is built into Lion OS, no? Third party perificials (or apps) can certainly cause conflicts and not work as well as advertised.
Also, seriously, I would get some tape, like duct tape, and tape up that loose power supply.
Why do you need something extra for your migration? (Or is the reason your old PowerPC G5 needs to run Lion but it can't?).
If that is the problem, here's an idea. Continue the canibalization of your PowerPC G5, take out it's hard drive(s). Buy an 'enclosure' to put the hard drive in and allow you to connect this hard drive to your new machine, the beautiful iMac i7, using the old hard drive as an external drive.
I did exactly this with my old PowerPC G5, using this enclosure, a Macally G-S350SUA, info at: http://www.macally.com/en/product/ipod4show.asp?ArticleID=215
I now use this for my Time Machine backups.
Re:What is the proper amount of time the computer needs to be unplugged? This would worry me. I turn off my comuter NOT by unplugging it but by holding the power on button for about 3-4 seconds and then it turns off.
I then wait 5 long seconds before pressing the power on button again to turn the computer back on.
Having to plug in and unplug and plug in and having to wait ten minutes for it to work is not normal.
Is there a power supply issue in your home, perhaps?
Considering the value of this machine and the fact that it may still be under warrenty, I'd consider the weeklong diagnostic. Would the machine have the same need to wait ten minutes to turn on at the Apple place?
What if you plug it in at a friend's house, or an office or library? Would it still take ten minutes before you could turn the machine on?
It might seem horrible to have to wait a week...or to do this again and again but I'd recommend taking full advantage of your warrenty, keep sticking this problem back to Apple and insist it gets made right. It will be worth it in the long run.

IMac powers down while starting in safe boot mode

My 2014 21" iMac powers itself down after about 10 seconds while trying to startup in safe boot mode. I'm not even sure why it is trying to start in safe boot mode. I shut it down after a power outage while plugged into an APS UPS. I'm guessing that since I interrupted the auto shutdown it is restarting in safe boot mode. Either way, I get a grey screen with a big apple and a progress bar. The progress bar gets to about a tenth full and the power just shuts off.
I've tried starting up while holding the alt key to select the Macintosh HD. The same thing happens.
I'm not particularly tech savvy. Any ideas are appreciated.

Thank you for the clarification and link. I ran the disk utility on Macintosh HD and it said it can't repair the disk, and that I need to reformat and restore. It has an invalid node structure. All of this happened just because I shut it down presumable while it was already trying to shut itself down after talking to the UPS?
At least I use Time Machine.
Thank you again.

Air shuts down before boot finishes

My MacBook was going really slow and I performed a forced shut down because it kept freezing. When I tried to start up again, it wouldn't boot past the Apple logo and the spinning wheel. I was told hold command, p, r and control while restarting could fix this so I tried. After that, the computer suddenly shut down shortly after getting to the boot screen.
Disk Utility won't work because it shuts down before it loads. Same for safe mode. It works in single-user mode and fsck returned the following:
disk0s2: I/O error.
Invalid node structure
(4, 0)
Invalid B-tree node size
(4, 0)
Invalid node structure
(4, 0)
Invalid B-tree node size
(4, 0)
** The volume could not be verified completely.
/dev/rdisk0s2 (hfs) EXITED WITH SIGNAL 8

The Disk Warrior tech site isn't working right now. You might send them a message asking if you can create a bootable DVD from the WIndows machine. You may be able to, if the file they sent is in the right image format. See this page to access their support db or send them a note: http://www.alsoft.com/Support/techsupportform.html

IMac Powers Down When On Sleep Mode?

Hello, I have been using an iMac at work and it just recently started powering down when left idle. This has been a reoccuring problem for a few days now and I would like to know a solution as soon as possible. Thank you.

Somebody? Anybody?

IMac powers down often

My iMac shuts down by itself sometimes. It wont go back on unless I remove all the cords in the back...power, network, usb's, etc... then it goes back on. Any advice?
I have apple care - if I go to genius bar and service is needed is that covered under apple care?

Generally, this is an issue which indicates that your power supply is defective.
AppleCare extensions to the original warranty cover the costs of parts and labor to replace such a defective supply.
You did not indicate which specific iMac model you have, but posted your inquiry in a forum for iMac flat panel models based on the G4 processor, none of which could be presently covered by a conventional AppleCare policy, as all such machines were manufactured and sold more than three years ago.

While in iMovie creating a movie or burning a movie to DVD my iMac will shut down before the process is completed

imovie shuts down my imac during the creating movie and burning process

It is possible that it is heat related. Monitor your drive temps
http://islayer.com/apps/istatpro/

17" early 2006 iMac powers down during startup

I am running 10.5.2 on an early 2006 1.86GHz Intel Core Duo 17" iMac (white), 160GB HD, 8x Superdrive, 2x1GB RAM.
1MB L2 Cache (from memory), bus speed 667 MHz (also from memory).
Latest BootROM (forget which one), checked for updates about a week ago.
Am, or rather was. It died this afternoon. I came back to it after lunch and the hard disk was making a distinctive pattern of clicks - a slow 1 - 2 - 3, which sounded like regular clicks and releases of a button, and then a short burst, followed by the 1 - 2 - 3 etc. The noises themselves weren't unusual, sounding just like ordinary disk access sounds, it was just the regular pattern that was distinctive, and the fact that none of my open apps were responding. I had been copying some files to the computer over the network and the copy had errored out with only a few files left to copy. Over the next 30-45 minutes I managed to force quit all the apps (about 7mins per program), but still couldn't shut down or restart, and ended up holding down the power button to switch the machine off.
I gave it half and hour's rest and powered it up, but it got stuck after the apple logo and the circle of spinning bars appeared (they were both still there). The hard disk made the distinctive pattern of sounds again.
The next time I started it, I tried zapping the PRAM, but the machine got to the same stage before powering itself down. Trying to boot into Safe mode or from my Leopard install DVD or in Target Disk Mode also failed. Every time, the Apple logo and the spinning circle of bars appeared, then the machine shut off, I presume before it can do any of those tasks.
I have tried taking each of the RAM modules out - same result.
I am not sure whether the problem is the hard disk, or the logic board or power supply, or something else entirely. I have heard on another forum that some iMacs went out with faulty capacitors on the logic boards and that you can check on Apple's website to see if your serial number falls into that range, but I can't find the page (search terms were intel imac logic board faulty capacitors power supply serial number, and variations thereof).
Recently I have installed several freeware and shareware apps from magazine DVDs, and had particular problems with Intego Fileguard. It creates 'safes' to encrypt folders you specify, though when I asked it to put my emails, pictures, movies and music in four separate safes they all became corrupted immediately. In the case of the pictures and music I lost most of the files (nearly all recoverable from backups/original CDs, thankfully!).
Also, just yesterday the machine had crashed after a restart, reaching the same point as it does now, but this time it didn't power off. When I powered it down and gave it a rest, it started up normally.
This is my first dead Mac, and I'm realising what a traumatic experience it can be. Help will be much appreciated!

Welcome to the Apple Discussions!
I would reset the System Management Controler.

GT72 2QE Dominator Pro powering down on boot

Hi, I'm having a problem with my new laptop. The scenarios are 2:
When using Intel VGA - Laptop will turn off on first boot but will load on 2nd attempt.
When using Nvidia 980M GTX - Following the switch from Windows to the dedicated VGA, the OS boots ok but once the system is powered off it will never boot again and laptop goes off.
I'm using the latest Nvidia and Intel drivers. This is getting frustrating. Any help will be much appreciated. Thanks!!

Thanks for the reply. I had already installed the latest version of BIOS i.e. E1781MS.10F with a fresh Windows 8.1 x64 but none solved the issue. I had a sleepless night to figure out what is wrong with this machine since I couldn't digest the fact that a 2400EUROS computer is faulty from factory. I bought this laptop from Poland last week and it was totally sealed in a giant package so surely I had to figure out what is wrong and I think I did. Just in case someone has my same experience please do the following:
1) Re-Update BIOS with the latest version 10F.
2) Re-Install Windows and install the WIFI and LAN driver from the MSI CD
3) Perform only Important updates no optional (for now)
3) DO NOT USE THE ONE CLICK INSTALL from the MSI CD
4) Install the latest Nvidia VGA driver from http://www.nvidia.com
5) Open the MSI Driver CD and start installing the devices one by one. Reboot between installations
6) Once done with the drivers, install the applications. Same thing here, reboot between installations
7) Download and install the latest Intel 4600 drivers from http://www.intel.com
I tried them all, only the above made it work. I have been testing the machine for the last 12hrs with no issues, well lets hope at least.
Thanks!!!

Satellite L350-20G powers down during boot up

My Satellite L350-20G starts to boot up and after 10 seconds powers off.
Also it refuses to charge.
We have exchanged fully charged battery packs with an identical model and same problem.

I have the same problem with my Toshiba L series laptop
I check the output DC voltage of the battery, it reads 10.8 Volts, 4000mAh Model No. PA35346-1BA5
The DC output voltage of the AC/DC adapter, reads 19 volts at 3,95 amperes Model ADP-75SB BB
i think the adapter output voltage is not compatible with voltage requirement of battery of the laptop.
Please check your battery and ac/dc adapter ratings which affects the battery life, maybe there is an over voltage limit switch installed on the motherboard which keeps the unit turning off whenever the ac/dc adapter is connected due to higher voltage rating.
I think the allowable output voltage requirement of the AC/DC adapter should only be up to 12Volts DC to minimize the heat produced during charging period.

IMAC Powering Off!

i am having issues with my Imac Powering down. i have had a tech review my computer and they say nothing is wrong.
current config is 20" Imac G5 Intel Core 2 Duo with most recent OS.
30" Apple Monitor run through DVI adaptor
Epson Photo R2400 via Firewire
original keyboard and mouse
has happened several times, do i need to have the firewire and usb cables for the monitor plugged in as well to assist in powering it?

PacNW, there is a service extension on the iMac G5 power supply. I am not sure based on your post what the issue is exactly, but check this:
http://www.apple.com/support/imac/powersupply/repairextension/
As for veichh, post in the other part of the forum that is based on "configurations" as well as networking, etc...
http://discussions.apple.com/forum.jspa?forumID=1111
Someone may have some knowledge about your printing issue.

My 2014 iMac with Yosemite keeps powering down overnight. It reboots fine. It did not do so before the Yosemite update. Help!

my 2014 iMac 27" powers down overnight after I installed Yosemite. It did not do so prior to the update. I just want it to sleep. How can I fix this? Thanks.

One last thought about a mac taking long to boot...try resetting the PRAM, that usually works.
1Shut down your computer completely. If you cannot access the shut down menu, you can hold the power button down until the machine shuts down. If this does not work, you can unplug it from the wall, but this is not recommended unless there is no other way to shut it down.
2Locate the "Command," "Option," "P" and "R" keys on your keyboard. The Command and Option keys are generally located directly to the left of your space bar. You will need to press these keys all at the same time, so be prepared to do so
3Turn on the iMac. Immediately press and hold down the "Command," "Option," "P" and "R" keys on your keyboard. This must be done before your computer displays the gray startup screen, otherwise it may not work.
4Continue holding the keys down until the computer restarts itself again, and you hear the startup chime. You may then release the keys, and your computer will boot up to your login screen or desktop

IMac 27'' keeps powering down for no reason

After about 2 hrs of editing sometimes my iMac 27'' keeps powering down for no reason and then rebooting.

If you have more than one user account, these instructions must be carried out as an administrator.
Launch the Console application in any of the following ways:
☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)
☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.
☞ Open LaunchPad. Click Utilities, then Console in the icon grid.
Step 1
Make sure the title of the Console window is All Messages. If it isn't, select All Messages from the SYSTEM LOG QUERIES menu on the left. If you don't see that menu, select
View ▹ Show Log List
from the menu bar.
Enter "BOOT_TIME" (without the quotes) in the search box. Note the timestamps of those log messages, which refer to the times when the system was booted. Now clear the search box and scroll back in the log to the last boot time after you had the problem. Select the messages logged before the boot, while the system was unresponsive or was failing to shut down. Copy them to the Clipboard (command-C). Paste into a reply to this message (command-V). Please include the BOOT_TIME message at the end of the log extract.
If there are runs of repeated messages, post only one example of each. Don’t post many repetitions of the same message.
When posting a log extract, be selective. In most cases, a few dozen lines are more than enough.
Please do not indiscriminately dump thousands of lines from the log into this discussion.
Important: Some private information, such as your name, may appear in the log. Anonymize before posting.
Step 2
Still in Console, look under System Diagnostic Reports for crash or panic logs, and post the entire contents of the most recent one, if any. In the interest of privacy, I suggest you edit out the “Anonymous UUID,” a long string of letters, numbers, and dashes in the header of the report, if present (it may not be.) Please don’t post shutdownStall, spin, or hang logs — they're very long and not helpful.

Powering down external HDs on an iMac when shut down

Hi to all, hope you can help .....
I recently added two external WD Studio HDs to my iMac connected as a RAID1 array. This was done using the Mac disc utility and without any reference to the pre installed WD software. I also have a separate Studio HD as my Time Machine and since all 3 have a Firewire connection I daisy chained the cable to all 3 devices (the iMac only has 1 Firewire port) since I thought this would be the fastest option. All 3 HDs appear to function correctly, except when I power my system down the drives remain awake.
Before I added the 2 in RAID array the original Time Machine HD did power down automatically when the Mac was turned off, so for some reason the system doesn't seem to want to cope with 3 HDs.
I've checked in system preferences/energy saving and the box for powering down HDs when possible is ticked.
Any ideas / solutions greatfully received, Cheers !!

Hi Roy,
I'd stick with Firewire. It's faster and I have always considered it more reliable. (It takes a technical discussion to explain why.)
There is no assurance that using USB will make your external drives power down. Again, I want to emphasize that not all drives will power down automatically when you shut down your Mac. Some drives do, some never do, and some have a 3-way switch that allows you to select the power-down behavior. And there may be something about your 2-drive software controlled RAID setup that affects things here.
The energy saver preference item for powering down drives whenever possible applies, I believe, only when the Mac is turned on and idle. (I do not believe it controls powering down external drives when you shut down your Mac.)
Unmounting the drive is as simple as what you wrote - eject it in the Finder. Alternatively, if you have the drive icons on your desktop, you can drag them to the trash to unmount the drive(s). Keep in mind that when you shut down your Mac, it automatically umounts the drives itself anyway.
External drives will automatically remount next time you start your Mac (unless the drive is powered off). If you unmount a drive and then decide you need to remount it while your Mac is still running, you can use Disk Utility. Open Disk Utility, select the drive you want to mount and then click the Mount button.

IMAC powers down before boot up is complete

Similar Messages

Maybe you are looking for