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.

Similar Messages

IMac won't turn on after power cut

When my iMac is unexpectedly turned off, ether at the wall or during a power cut, it won't then come back on immediately. Sometimes it will come back on after an hour, sometimes after a couple of days. Anyone know why this is? There is no logic to it. I've tried all the trouble shooting stuff; the resetting SMC for example. And I've got a surge protector. I've also taken it into an Apple store, a round trip of 3 hours, twice already over the past couple of months. But after doing some diagnostic tests on it they can find nothing wrong. Also, when they go to turn it on, it fires up immediately. I was told that unless they experience the problem themselves they can't do anything. Which means I'm forever taking it in to them, during this problem, on the off chance it may still be a problem when I get there. It's very infuriating. Help!!!

Great advice. And I'll definitely do that - need to get my Mac back on and working before that however.

My iMac won't turn on after power flickered on and off.Is there a virus affecting it or is something ele wrong?

My iMac was on and we had our power flicker because of weather conditions. I know the computer is hooked up right because it was on before the power went out.So my question is, is there a virus that had been affecting it before it went off, or is the power button broken? And any help would be appreciated because we have just taken in other computers for various reasons and we really don't want to take it in again.Oh, and i don't really know which model it is. Thanks

Try an SMC reset - sometimes works:
SMC Reset
Shut down the computer.
Unplug the computer’s power cord and disconnect peripherals (printers/external hard disks, etc. but not keyboard or mouse).
Press and hold the power button for 5 seconds.
Release the power button.
Attach the computers power cable.
Press the power button to turn on the computer.

2008 iMac won't turn on after Mountain Lion installation

I have a 2008 iMac with 6GB of RAM that was running on OS X 10.6.8 perfectly. Tonight I upgraded it to Mountain Lion. After the installation, my machine was running slower and a little choppy, especially when first opening programs, even though it meets all the requirements for Mountain Lion. After about an hour or two of running like this, I was standing away from the computer for a minute when I saw a flash come from the monitor. I went to it and the screen was black. I thought maybe it had went to sleep, but nope! It was completely off and would not turn back on. No lights or sounds come on at all. There was no power outage or anything, and all other devices plugged into the same surge protector were working fine. I tried plugging it into another outlet and still had no luck.
Any insight onto what caused this? Is it most likely a power supply failure, and could this have been caused by the Mountain Lion installation? Considering I've had this computer for almost 5 years and this has never happened before, it seems obvious that this contributed somehow.
Any advice would be appreciated. I'm going to try to take it to an Apple store soon, but the earliest appointment is a few days away.
Thank you!

Welcome to Apple Support Communities
It's quite possible that the power supply failed. The failure is difficult to be related with OS X Mountain Lion, so I would discard that. In some cases, it's normal that you experience slowness after installing a new OS X version because Spotlight indexes the hard drive.
The best you can do is to take it to an Apple Store or reseller so you can get your Mac diagnosed. Now we can't do anything else apart from thinking that is a power supply issue

Old imac won't turn on after a week of inactivity

Hello,
I'm aware this question was answered elsewhere on this forum but the issue there seemed to be that the imac had been moved and/or jolted. In my case, I went to New York for a week and when I came home the imac just wouldn't turn on. I've bought a new power cable, checked all the connections, disconnected peripherals, tried command/control/power etc. Nothing. I've even tried starting from a Norton utilities disk.
There were no date/time issues the last time I used it but is it possible this could be a battery problem? Any thoughts why it might have just stopped after a week of not using it? (I normally have the computer on every day).
Please help!
Thanks,
KH
Imac G3 Mac OS 9.0.x Slot loading CD, Bondi blue

Hi dancebaby,
Thanks for visiting Apple Support Communities.
Start with these troubleshooting steps if your iPhone does not turn on:
iPhone: Hardware troubleshooting
http://support.apple.com/kb/TS2802
Will not turn on, will not turn on unless connected to power, or unexpected power off
Verify that the Sleep/Wake button functions. If it does not function, inspect it for signs of damage. If the button is damaged or is not functioning when pressed, seek service.
Check if a Liquid Contact Indicator (LCI) is activated or there are signs of corrosion. Learn about LCIs and corrosion.
Connect the iPhone to the iPhone's USB power adapter and let it charge for at least ten minutes.
After at least 30 minutes, if:
The home screen appears: The iPhone should be working. Update to the latest version of iOS if necessary. Continue charging it until it is completely charged and you see this battery icon in the upper-right corner of the screen . Then unplug the phone from power. If it immediately turns off, seek service.
The low-battery image appears, even after the phone has charged for at least 20 minutes: See "iPhone displays the low-battery image and is unresponsive" symptom in this article.
Something other than the Home screen or Low Battery image appears, continue with this article for further troubleshooting steps.
If the iPhone did not turn on, reset it while connected to the iPhone USB power adapter.
If the display turns on, go to step 4.
If the display remains black, go to next step.
Connect the iPhone to a computer and open iTunes. If iTunes recognizes the iPhone and indicates that it is in recovery mode, attempt to restore the iPhone. If the iPhone doesn't appear in iTunes or if you have difficulties in restoring the iPhone, see this article for further assistance.
If restoring the iPhone resolved the issue, go to step 4. If restoring the iPhone did not solve the issue, seek service.
Best,
Jeremy

IMac won't turn on after resetting SMC

Recently my 2011 iMac starts uttering strange noise even if the fan speed is low so I decided to reset SMC this morning. However, after unplugging for 15 sec and plug again. it just won't start! No matter how I pressed the power button, there is no reaction coming from my iMac. I tried to long press for 10 more seconds, re-unplug and plug in, and tried another socket on the wall but in vain. Do you have other ideas 'cause I have not backup my data and hope to grab something output before sending it to the APPLE store. Thanks.

If you get no video or audio at all and you have confirmed it's not the power source or power cord then that indicates your power supply may have failed.

IMac won't turn on after scheduled shut down

Hi, hope someone here can help me!
I have a 20" 2006 iMac. While it was still under warranty, it repeatedly froze, and eventually when I turned it on the screen remained blank although I could hear that the hard drive was at least trying to get started. I got it repaired (new logic board, new screen), but now I am having some of the other difficulties mentioned here, where the screen freezes when using graphic intense software, including 3D games. Sometimes, it works fine for hours, others less than 2 minutes. I used to keep it on all the time, with energy saver set to go to sleep when possible. I've found, though that the graphics problems are less likely to happen if it has been off at least overnight, so I set up the schedule for it to turn itself off in the small hours. The problem is, when I go to turn it back on, it won't come on unless i pull out the power cable from the back of it and put it back in again. Any ideas what's causing this? And any ideas on what I can do to fix it?
Thanks

This just happened to me today. Not sure what to do as yours was the only discussion like this.
Please let me know if you were able to restore it and how?
Extremely frustrated since it was brand spankin new!!

IMAC won't turn on after installing Magic Mouse

Hello
I Have an intel 2 core duo aluminum. I installed the magic mouse and now I cannot star it. I get the Grey screen, Some time with the apple, some times just the gray screen. When I load the installer disk and run disk utility, the hard drive does not show up. Any Idea on how to fix my problem?
Thank you
Raoul

I'm afraid so. Still. I wonder how it just happened the exact moment I installed the magic Mouse. Thought it could be a compatibility issue
Thanks anyway
Raoul

Since download of Firefox Hello desktop & laptop both on Windows 7 are very slow even after refresh, download history removed and anti virus software turned off

Since download of Firefox Hello my home desktop & laptop, both on Windows 7, are very slow to open. I have refreshed firefox, removed download history and turned off the anti virus software in extensions. All the plugins are up to date. Can we revert back to Firefox without Firefox Hello?

Firefox Hello is simply a wrapper for technology already in Firefox, it doesn't negatively impact performance if you aren't using it. Are you saying that your entire computer is slow or just Firefox?

IMac 5K won't turn on after 3 weeks.

I have used only for 3 weeks.
Suddenly, iMac screen turned to black.
There are no clue of turn on.
I brought it to apple store on 4/16 and it is still in repair.
About 1 week ago, they were waiting for logic board and on Tuesday I got an call saying they will receive it shortly and still in process.
I used 3 weeks and I am waiting more than 3 weeks to get the product and be repaired.
Does any one have similar issue? How long does apple store normal take for repair iMac?
Am I just bad luck?

I have been having exactly the same problem as Mhuntet11.
My 2010 i3 iMac will not turn on after losing power, which includes being unplugged or the power being turned off.
It has happened to me 4 times now. In each case - nothing will get it started. But on each occasion - about 2 days after the power cut - the iMac will start up again, good as new.
I have also experienced the other thing that Mhuntet11 said:
"when it won't turn on I plug it into a different outlet and if it does turn on I can unplug it and put it back in the original outlet and it works fine"
Yep - once, after 2 days of trying every power point in the house, I finally started up in the kitchen. Not very practical, so I bit the bullet and powered it down again and moved it back to the office. It stared fine.
Does this sound like a fault that should be serviced? Or is there some re-set technique I do not know about.
I have followed the SMC reset procedure and it does nothing

IMac 2ghz won't turn on after power loss

I really hope someone can help me. My 07 or 08 2 ghz iMac will not turn on after losing power which includes being unplugged or the power being turned off. This happens whether or not it is shut down properly. Once it will not turn on it must be unplugged and sit for about 12 hours or be plugged into a different outlet. Outlets are all fine. Have reset pram and all that stuff. It is surge protected. Any suggestions? Thanks

I have been having exactly the same problem as Mhuntet11.
My 2010 i3 iMac will not turn on after losing power, which includes being unplugged or the power being turned off.
It has happened to me 4 times now. In each case - nothing will get it started. But on each occasion - about 2 days after the power cut - the iMac will start up again, good as new.
I have also experienced the other thing that Mhuntet11 said:
"when it won't turn on I plug it into a different outlet and if it does turn on I can unplug it and put it back in the original outlet and it works fine"
Yep - once, after 2 days of trying every power point in the house, I finally started up in the kitchen. Not very practical, so I bit the bullet and powered it down again and moved it back to the office. It stared fine.
Does this sound like a fault that should be serviced? Or is there some re-set technique I do not know about.
I have followed the SMC reset procedure and it does nothing

My imac won't turn on a1311 intel core i3 late 2010

Hey, today after a power off my iMac won't turn on, I've tried reseting it plugging it and holding the power button but nothing happens, im really worried, i have to finish an edition and have al native videos there... HELP!

check out this discussion.
you should definitely get a decent UPS to protect your investment.
something like the APC Back-UPS ES 700 should suffice.

Anti Virus Software for iMAC

I have just taken delivery of my new iMAC and what Anti Virus Software would one recommend or NONE at all ? I see on reviews Intego Mac is highly rated

1. This comment applies to malicious software ("malware") that's installed unwittingly by the victim of a network attack. 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.
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.
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 actually been tested by Apple (unless it comes from the Mac App Store), 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. For most practical purposes, applications recognized by Gatekeeper as signed can be considered safe.
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 find some other way to evade Apple's controls.
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 presumably effective against known attacks, but maybe not against unknown attacks. It notifies you if it finds malware, but otherwise there's no user interface to MRT.
5. Beyond XProtect, Gatekeeper, and MRT, there’s no evidence of any benefit from other automated protection against malware. The first and best line of defense is always 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 never use software that comes from an untrustworthy source. How do you know whether a source is trustworthy?
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 untrustworthy.
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 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.
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 from malware.
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. If you need to be able to detect Windows malware in your files, use the free softwareClamXav — 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.
By modifying the operating system, the software itself may create weaknesses that could be exploited by malware attackers.
8. 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.
ClamXav 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
ClamXav may be able to tell you which particular virus or trojan it is, but do you care? In practice, there's seldom a reason to use ClamXav unless a network administrator requires you to run an anti-virus application.
9. The greatest harm done by security software, in my opinion, is in its effect on human behavior. It does little or nothing to protect people from emerging threats, but if they get a false sense of security from it, they may feel free to do things that expose them to higher risk. Nothing can lessen the need for safe computing practices.
10. 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.

Does my iMac need anti-virus software

I've read recently that iMacs have been susceptable to viruses. Does my iMac need anti-virus software? And if so, d0es Apple recommend any one in particular?

Mac OS X versions 10.6.7 and later have built-in detection of known Mac malware in downloaded files. The recognition database is automatically updated once a day; however, you shouldn't rely on it, because the attackers are always at least a day ahead of the defenders. In most cases, there’s no benefit from any other automated protection against malware.
The most effective defense against malware is your own intelligence. All known malware that affects a fully-updated installation of Mac OS X 10.6 or later takes the form of trojans, which can only work if the victim is duped into running them. If you're smarter than the malware attacker thinks you are, you won't be duped. That means, primarily, that you never install software from an untrustworthy source. How do you know a source is untrustworthy?
Any website that prompts you to install a “codec,” “plug-in,” or “certificate” that comes from that same site, or an unknown site, merely in order to use the site, is untrustworthy.
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.
“Cracked” versions of commercial software downloaded from a bittorrent are likely to be infected.
Software with a corporate brand, such as Adobe Flash Player, must be downloaded directly from the developer’s website. No intermediary is acceptable.
Disable Java (not JavaScript) in your web browser(s). Few websites have Java content nowadays, so you won’t be missing much. This setting is mandatory in Mac OS X 10.5.8 or earlier, because Java in those versions has bugs that make it unsafe to use on the Internet. Those bugs will probably never be fixed, because those older operating systems are no longer being maintained by Apple. Migrate to a newer version of the Mac OS as soon as you can.
Follow these guidelines, and you’ll be as safe from malware as you can reasonably be.
Never install any commercial "anti-virus" products for the Mac, as they all do more harm than good. If you need to be able to detect Windows malware in your files, use ClamXav — nothing else.

I have what appears to be a virus on my Mac namely MAL/FAK AV-OQ how can I remove it? I have only discovered after running SOPHOS anti virus software???

I have what appears to be a virus on my mac namely MAL/FAK AV-OQ I only discovered it after installing SOPHOS anti virus software.
I cannot remove it automatically with this software it says it has to be done manually.
Where do I start???
Help req'd urgently

That is Windows malware, and cannot affect your Mac. See:
http://www.sophos.com/en-us/threat-center/threat-analyses/viruses-and-spyware/Ma l~FakeAV-OQ.aspx
It may be attached to an e-mail message or could be something that was copied over from a Windows machine via flash drive or something similar. If it is attached to an e-mail message, simply delete the e-mail. (Do not let Sophos, or any other anti-virus software, quarantine the message or attachment! That can corrupt the mailbox that the message resides in.) If it isn't an e-mail message, you can let Sophos quarantine and delete the file or you can delete it yourself.

Imac won't turn on after anti virus software downloaded

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