My Imac won't turn on. Randomly shut down and randomly shuts off

Yesterday night i was working on my imac and left it on for about an hour leaving the desk. When i came back it was shut down and wasn't able to turn it on. This morning i unplugged it and plugged it to another plug and it turned on. After a while it turned of again and wouldn't turn on. I re-changed plugs here and there with random success. I then changed the the ram as i had put 2x2gb instead of the original 1x1gb si i replaced the original one and it turned on. So to make sure it was the ram i re-inserted the 2gb but it wouldn't turn on and to my great disappointment it wouldn't turn on when i re-inserted the 1gb original ram either... Bit lost. Not sure if it has to do with temperature issues?
Please help!!!!

Sounds like either an unseated or bad Ram module.
Try pushing real hard on each module with both thumbs to insure that they are firmly seated in the slots.

Similar Messages

Mini spontaneous shut-down and application shut-down problem

Help!
I've searched. I've read. I can't find the answer!
After I updated my firmware several weeks ago (to SMC 1.3f4), I've had problems with spontaneous shut-down of the computer, and a frustrating application shut-down issue (Safari, Mail, Word--you name it!).
I tried to find the other firmward update from last summer, which I read about in several posts from July/August, but the link is dead (Mac Mini Firmware update 1.0.1).
Coincidentally, after an office break-in two weeks ago, I FileVaulted my computer. I thought my problem must have to do with that, but all the posts I can find here are about this firmware thing.
Should I/can I reinstall the SMC 1.3f4 update? Is there some secret to the no-longer-available 1.0.1 update?
Can anyone help me? (I would certainly appreciate it!)
Garth
iMac Intel, Mac Mini Intel, Powerbook G4 Mac OS X (10.4.8)

Try a safe boot, hold the shift key and power up, this will take a little loner than normal, hold the shift till you see the progress bar. See if it works normal, if it does than it is more than likely some 3rd party software.Then restart normal and check your console for panics. That would be your isssue. You can also start holding command R and restoring from utililities. Back up before you do anything.

MacBook randomly shut down, and won't turn back on

First of all, hello. Secondly, I've got a problem with my MacBook: about half an hour ago, it randomly shut down and when I tried to turn it back on, it didn't. Instead, the backlight kept flickering at the tempo that something inside the computer was "clicking", and the longer I held the power button, the more "clicks" there were. Needless to say, I've tried charging the battery, resetting the SMC, and to no avail: I still can't power it up, even when I don't use my battery. Whether I use it or not, the MacBook still "clicks" during my pressing of the power button and stops "clicking" when I release it. My MacBook is a year old. Can someone help me out here?

Me too. Any resolution? I don't want to take it to my local apple place because they're retards, but according to the info on my warranty that's the only place available. Can't believe they don't have an RMA service direct to Cupertino, what a joke.

My Intel imac won't turn on

Hi! My intel Imac suddenly, and without apparent reason, shut down, and won't turn back on. When I press the power button, sometimes it makes a small noise, but then nothing happens. I have unplugged all the cables, and also tried resetting the SMC, and still nothing. I see some of you have had a similar problem, I don't know if any of you found out the reason why this happens. The computer is almost brand new (I've had it for 3 months) and up until now I had had no problem with it.
Thank you!
Nadia

You've (unfortunately) joined the growing list of users that are having problems with their iMac. Mine was purchased in September 2007 and I went through two bad ones before I finally kept one until last week.
Last week: the iMac totally died. It's at the Apple store getting the logic board and PSU replaced. Look through this forum and you'll see a number of other users with random reboots and dead iMacs.

My Macbook Pro just randomly shuts down and I have to plug it into power to be able to turn it back on. Anybody got any suggestions?

My Macbook Pro just randomly shuts down and I have to plug it into power to be able to turn it back on. Anybody got any suggestions?

Troubleshooting: My computer won't turn on
Power or other problems related to unexpected system sleep, shutdown, lights or fans call for an SMC reset. Read all the steps.
Before Resetting the SMC
Try each of the following steps in this order before you reset the SMC. Test the issue after completing each troubleshooting step to determine if the issue still occurs.
Press Command + Option + Escape to force quit any application that is not responding.
Put your Mac to sleep by choosing the Apple () menu from the upper-left menu bar and then choosing Sleep. Wake the computer after it has gone to sleep.
Restart your Mac by choosing the Apple () menu from the upper-left menu bar and then choosing Restart.
Shut down your Mac by choosing the Apple () menu from the upper-left menu bar and then choosing Shut Down.
Resetting the SMC on portables with a battery you should not remove on your own
Shut down the computer.
Plug in the MagSafe power adapter to a power source, connecting it to the Mac if it's not already connected.
On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
Release all the keys and the power button at the same time.
Press the power button to turn on the computer.

Since installing OSX 10 my iMac randomly shuts down and restarts. I can not determine why this is happening. Any ideas?

Since installing OSX 10, my iMac randomly shuts down and restarts. I can not determine why this is happening. Any ideas?

1. This is a comment on what you should and should not do to protect yourself from malicious software ("malware") that circulates on the Internet. It does not apply to software, such as keystroke loggers, that may be installed deliberately by an intruder who has hands-on access to the victim's computer. That threat is in a different category, and there's no easy way to defend against it. If you have reason to suspect that you're the target of such an attack, you need expert help.
If you find this comment too long or too technical, read only sections 5, 6, and 10.
OS X now implements three layers of built-in protection specifically against malware, not counting runtime protections such as execute disable, sandboxing, system library randomization, and address space layout randomization that may also guard against other kinds of exploits.
2. All versions of OS X since 10.6.7 have been able to detect known Mac malware in downloaded files, and to block insecure web plugins. This feature is transparent to the user, but internally Apple calls it "XProtect." The malware recognition database is automatically checked for updates once a day; however, you shouldn't rely on it, because the attackers are always at least a day ahead of the defenders.
The following caveats apply to XProtect:
It can be bypassed by some third-party networking software, such as BitTorrent clients and Java applets.
It only applies to software downloaded from the network. Software installed from a CD or other media is not checked.
As new versions of OS X are released, it's not clear whether Apple will indefinitely continue to maintain the XProtect database of older versions such as 10.6. The security of obsolete system versions may eventually be degraded. Security updates to the code of obsolete systems will stop being released at some point, and that may leave them open to other kinds of attack besides malware.
3. Starting with OS X 10.7.5, there has been a second layer of built-in malware protection, designated "Gatekeeper" by Apple. By default, applications and Installer packages downloaded from the network will only run if they're digitally signed by a developer with a certificate issued by Apple. Software certified in this way hasn't necessarily been tested by Apple, but you can be reasonably sure that it hasn't been modified by anyone other than the developer. His identity is known to Apple, so he could be held legally responsible if he distributed malware. That may not mean much if the developer lives in a country with a weak legal system (see below.)
Gatekeeper doesn't depend on a database of known malware. It has, however, the same limitations as XProtect, and in addition the following:
It can easily be disabled or overridden by the user.
A malware attacker could get control of a code-signing certificate under false pretenses, or could simply ignore the consequences of distributing codesigned malware.
An App Store developer could find a way to bypass Apple's oversight, or the oversight could fail due to human error.
For the reasons given above, App Store products, and other applications recognized by Gatekeeper as signed, are safer than others, but they can't be considered absolutely safe. "Sandboxed" applications may prompt for access to private data, such as your contacts, or for access to the network. Think before granting that access. Sandboxing security is based on user input. Never click through any request for authorization without thinking.
4. Starting with OS X 10.8.3, a third layer of protection has been added: a "Malware Removal Tool" (MRT). MRT runs automatically in the background when you update the OS. It checks for, and removes, malware that may have evaded the other protections via a Java exploit (see below.) MRT also runs when you install or update the Apple-supplied Java runtime (but not the Oracle runtime.) Like XProtect, MRT is effective against known threats, but not against unknown ones. It notifies you if it finds malware, but otherwise there's no user interface to MRT.
5. The built-in security features of OS X reduce the risk of malware attack, but they're not absolute protection. The first and best line of defense is always going to be your own intelligence. With the possible exception of Java exploits, all known malware circulating on the Internet that affects a fully-updated installation of OS X 10.6 or later takes the form of so-called "Trojan horses," which can only have an effect if the victim is duped into running them. The threat therefore amounts to a battle of wits between you and the malware attacker. If you're smarter than he thinks you are, you'll win.
That means, in practice, that you always stay within a safe harbor of computing practices. How do you know what is safe?
Any website that prompts you to install a “codec,” “plug-in,” "player," "extractor," or “certificate” that comes from that same site, or an unknown one, is unsafe.
A web operator who tells you that you have a “virus,” or that anything else is wrong with your computer, or that you have won a prize in a contest you never entered, is trying to commit a crime with you as the victim. (Some reputable websites did legitimately warn visitors who were infected with the "DNSChanger" malware. That exception to this rule no longer applies.)
Pirated copies or "cracks" of commercial software, no matter where they come from, are unsafe.
Software of any kind downloaded from a BitTorrent or from a Usenet binary newsgroup is unsafe.
Software that purports to help you do something that's illegal or that infringes copyright, such as saving streamed audio or video for reuse without permission, is unsafe. All YouTube "downloaders" are outside the safe harbor, though not all are necessarily harmful.
Software with a corporate brand, such as Adobe Flash Player, must be downloaded directly from the developer’s website. If it comes from any other source, it's unsafe. For instance, if a web page warns you that Flash is out of date, do not follow an offered link to an update. Go to the Adobe website to download it, if you need it at all.
Even signed applications, no matter what the source, should not be trusted if they do something unexpected, such as asking for permission to access your contacts, your location, or the Internet for no obvious reason.
"FREE WI-FI !!!" networks in public places are unsafe unless you can verify that the network is not a trap (which you probably can't.) Even then, do not download any software or transmit any private information while connected to such a network, regardless of where it seems to come from or go to.
6. Java on the Web (not to be confused with JavaScript, to which it's not related, despite the similarity of the names) is a weak point in the security of any system. Java is, among other things, a platform for running complex applications in a web page, on the client. That was always a bad idea, and Java's developers have proven themselves incapable of implementing it without also creating a portal for malware to enter. Past Java exploits are the closest thing there has ever been to a Windows-style virus affecting OS X. Merely loading a page with malicious Java content could be harmful.
Fortunately, client-side Java on the Web is obsolete and mostly extinct. Only a few outmoded sites still use it. Try to hasten the process of extinction by avoiding those sites, if you have a choice. Forget about playing games or other non-essential uses of Java.
Java is not included in OS X 10.7 and later. Discrete Java installers are distributed by Apple and by Oracle (the developer of Java.) Don't use either one unless you need it. Most people don't. If Java is installed, disable it — not JavaScript — in your browsers.
Regardless of version, experience has shown that Java on the Web can't be trusted. If you must use a Java applet for a task on a specific site, enable Java only for that site in Safari. Never enable Java for a public website that carries third-party advertising. Use it only on well-known, login-protected, secure websites without ads. In Safari 6 or later, you'll see a lock icon in the address bar with the abbreviation "https" when visiting a secure site.
Follow the above guidelines, and you’ll be as safe from malware as you can practically be. The rest of this comment concerns what you should not do to protect yourself.
7. Never install any commercial "anti-virus" or "Internet security" products for the Mac, as they all do more harm than good, if they do any good at all. Any database of known threats is always going to be out of date. Most of the danger is from unknown threats. If you need to be able to detect Windows malware in your files, use one of the free anti-virus products in the Mac App Store — nothing else.
Why shouldn't you use commercial "anti-virus" products?
Their design is predicated on the nonexistent threat that malware may be injected at any time, anywhere in the file system. Malware is downloaded from the network; it doesn't materialize from nowhere.
In order to meet that nonexistent threat, the software modifies or duplicates low-level functions of the operating system, which is a waste of resources and a common cause of instability, bugs, and poor performance.
To recognize malware, the software depends on a database of known threats, which is always at least a day out of date. Most of the real danger comes from highly targeted "zero-day" attacks that are not yet recognized.
By modifying the operating system, the software itself may create weaknesses that could be exploited by malware attackers.
8. An anti-malware product from the App Store, such as "ClamXav," doesn't have these drawbacks. That doesn't mean it's entirely safe. It may report email messages that have "phishing" links in the body, or Windows malware in attachments, as infected files, and offer to delete or move them. Doing so will corrupt the Mail database. The messages should be deleted from within the Mail application.
An anti-virus app is not needed, and should not be relied upon, for protection against OS X malware. It's useful only for detecting Windows malware. Windows malware can't harm you directly (unless, of course, you use Windows.) Just don't pass it on to anyone else.
A Windows malware attachment in email is usually easy to recognize. The file name will often be targeted at people who aren't very bright; for example:
♥♥♥♥♥♥♥♥♥♥♥♥♥♥!!!!!!!H0TBABEZ4U!!!!!!!.AVI♥♥♥♥♥♥♥♥♥♥♥♥♥♥.exe
Anti-virus software may be able to tell you which particular trojan it is, but do you care? In practice, there's seldom a reason to use the software unless an institutional policy requires it.
The ClamXav developer won't try to "upsell" you to a paid version of the product. Other developers may do that. Don't be upsold. For one thing, you should not pay to protect Windows users from the consequences of their choice of computing platform. For another, a paid upgrade from a free app will probably have the disadvantages mentioned in section 7.
9. It seems to be a common belief that the built-in Application Firewall acts as a barrier to infection, or prevents malware from functioning. It does neither. It blocks inbound connections to certain network services you're running, such as file sharing. It's disabled by default and you should leave it that way if you're behind a router on a private home or office network. Activate it only when you're on an untrusted network, for instance a public Wi-Fi hotspot, where you don't want to provide services. Disable any services you don't use in the Sharing preference pane. All are disabled by default.
10. As a Mac user you don't have to live in fear that your computer may be infected every time you install software, read email, or visit a web page. But neither should you assume that you will always be safe from exploitation, no matter what you do. The greatest harm done by security software is precisely its selling point: it makes people feel safe. They may then feel safe enough to take risks from which the software doesn't protect them. Nothing can lessen the need for safe computing practices.

IMac shuts down at random, any ideas on cause?

My iMac (G5, no iSight)has in the last 2 weeks started to shut down at random, for example last night it shut down twice in a two hour period. It makes one click noise when it does this and all power is immediately lost. So far it always starts up straight away when the power button is pushed. I did have the power board? replaced a few years ago under Apples extended warrenty scheme and it has been fine since then. I have noticed a few other similar posts and my questions are: does this sound serious and what is causing it, could it be linked to the same issue as the warrenty scheme replacement? is there anything I can do to put right without a big bill coming my way!?
Regards,
David.

Welcome to Discussions - it sounds as if your power supply unit is failing, and yes, it could be the same problem as before. Unfortunately, Apple's extended warranty expired last year, so you would have to bear the expense yourself. However, first try vacuuming all the air vents, and open the machine up and vacuum the fans. This could help, as well as resetting the SMU
1. Turn off the computer by choosing Shut Down from the Apple menu, or by holding the power button until the computer turns off.
2. Unplug all cables from the computer, including the power cord.
3. Wait 10 seconds.
4. Plug in the power cord while simultaneously pressing and holding the power button on the back of the computer.
5. Let go of the power button.
6. Press the power button once more to start up your iMac.
Let us know how you make out,

My IMAC seems to have died after power surge. It shut down and won't start. What shall I do?

my IMAC seems to have died after power surge. It shut down and won't start. What shall I do?

I would recommend you try an SMC reset at this point:
Resetting the System Management Controller (SMC)
Resetting the SMC for Mac Pro, Intel-based iMac, Intel-based Mac mini, or Intel-based Xserve
Shut down the computer.
Unplug the computer's power cord.
Wait fifteen seconds.
Attach the computer's power cord.
Wait five seconds, then press the power button to turn on the computer.
If that fails to solve it, it is probable that the power surge damaged some of your iMac's hardware components, and will need to be repaired at an Apple Authorized Service Center.

My iPhone 4 shut down and won't turn on again.What should i do?

My iPhone 4 shut down and won't turn on again. I tried charging it and do it again...When i charge it , it opens the " Connect to iTunes" , when i switch to the computer to connect it , it doesn't work... It starts to the apple screen , and then just shuts down again. I tried holding the home and sleep/wake button at the same time..I tried everything. What should i do?

Your iPhone is going back and forth between recovery mode and powering on which is really strange.
Have you tried a hardware reset while its connected to your computer? This will force it back into recovery mode so that you can restore it. If restoring and setting up as new doesn't help, go ahead and take it to an Apple Store for a replacement

IPhone 5 shut down and won't turn back on

My phones screen turned a blue/greenish color and shut down and will not turn back on :(

I'm having the same issue with my iPhone5. It just started yesterday afternoon. The "hard reset" as you suggested worked once. However, it shut down again only one hour later. It didn't turn on (even with the hard reset) for three hours when the hard reset worked again. I hooked it up to iTunes and restored my phone and thought that it would fix the issue. But after being on for about two hours, my screen got vertical lines then turned green and shut off again. I haven't been able to turn it back on no matter what I do all night and all day today.
It doesn't matter that the phone is plugged in or have 100% battery power. It just won't turn on again.
I have an appointment at my local Apple Genuis Bar, but I'm not sure what they can do as I'm not sure if this is a software or a hardware issue.

I have an older IMac 5. I installed snow Leopard on. Now my DVD drive is not working. Discs go in but it dosn't boot up or show in finder. Then disc won't eject unless i shut down and restart. HELP !

I have an older IMac 5. I installed snow Leopard on. Now my DVD drive is not working. Discs go in but it dosn't boot up or show in finder. Then disc won't eject unless i shut down and restart. HELP !

Snow Leopard cannot run on a PPC G5 Mac as it requires an Intel processor. Please confirm what Mac you have.

New iMac shutting down and starting up randomly

My new iMac shuts down and starts up at random (over and over again usually in the first few minutes of start up). I ran a test with the TechTool Deluxe and the test involving "video" failed (all other tests passed). What do I do now? Help!!
Thank you!

Welcome to Discussions - if your iMac is new, it's an intel and you can post on their forum, they'll be able to he you better. However, your first thought should be to call Apple, you have 90 days of free telephone help, and a year's warranty. Since what you are describing sounds like a hardware problem, even if you 90 days are up, call Apple (they will provisionally charge your credit card, but will remit the charge if the problem is hardware related). They will take care of the problem.

2011 iMac keeps shutting down at random after Mavericks install.

Installed Mavericks day 1 of the public build on App Store and ever since my Mac will just randomly shut down and not let me power it back up. Only has happened when browsing the web and after shut down I have removed power cord from iMac and wall, and also tried different outlets and nothing the first two times I was able to get it back up and running after about 20 minutes of it just being off. Third time it happened I was not so lucky, made an genius appt and they ran diagnostic test and checked power cord and it of course worked fine for them, took it home and booted instantly... Now 24 hours later it just shut off again and no luck getting it going. Suggestions please or should I schedule another appt and have them send it in?

Installed Mavericks day 1 of the public build on App Store and ever since my Mac will just randomly shut down and not let me power it back up. Only has happened when browsing the web and after shut down I have removed power cord from iMac and wall, and also tried different outlets and nothing the first two times I was able to get it back up and running after about 20 minutes of it just being off. Third time it happened I was not so lucky, made an genius appt and they ran diagnostic test and checked power cord and it of course worked fine for them, took it home and booted instantly... Now 24 hours later it just shut off again and no luck getting it going. Suggestions please or should I schedule another appt and have them send it in?

Imac won't turn on after anti virus software downloaded

The Avast antivirus software was downloaded onto my imac and now my imac won't turn on. What should I do?

Troubleshooting: My computer won't turn on
Read and follow all the steps.
If you find yourself at Step 6 determine if you can start the Mac in "Safe Mode":
Safe Mode or "Safe Boot" is a troubleshooting mode that bypasses all third party system extensions and loads only required system components. Read about it: Starting up in Safe Mode
You must disable FileVault before you can start your Mac in Safe Mode.
Starting your Mac in Safe Mode will take longer than usual, graphics will not render smoothly, audio is disabled on some Macs, and some programs (iTunes for example) may not work at all.
Merely starting your Mac in Safe Mode is not intended to resolve the problem, it's to observe its performance without certain additional components.
To end Safe Mode restart your Mac normally. Shutdown will take longer as well.
Remove the Avast garbage by using its uninstaller. Never install it, or anything like it, ever again.

IMac won't turn on. Only a clicking sound and a grey folder with flashing question mark.

iMac won't turn on. Only a clicking sound and a grey folder with flashing question mark.
Help.

Your iMac is actually turning ON as proven by the grey folder with the flashing question mark.
The flashing question mark indicates that your system is unable to find a bootable volume. The clicking sound that you hear is probably coming from your hard drive while it tries to recalibrate. I suspect your hard drive has failed.
What model imac do you have? If it's under warranty I suggest taking it in for service. Hopefully you've been maintaining a regular backup of your data as all users should. I lost my data once and it was a valuable lesson. I back up regularily now.
If your iMac came with install disks then you can boot from them, choose your language when asked, then pull down the Utilities menu to launch the Disk Utility application. The Disk Utility application will allow you to verify whether your hard drive has an issue. Usually a clicking sound, assuming it's coming from the hard drive, is a sign of a bad hard drive.
If your system has Lion installed then you can hold down the Command and R keys when you restart the system, then launch the Disk Utility application from the menu that appears.

My Imac won't turn on. Randomly shut down and randomly shuts off

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