IMac keeps cycling on and off

My iMac mysteriously starts up by itself and then shuts down by itself. I didn't touch it for 2 weeks and after I went to use it, it now just keeps cycling up and down. The only way to stop it is to keep it unplugged. Any insights? Thanks.

Hello and Welcome to Apple Discussions. 
Here are some things to try:
Check your Energy Saver settings (the iMac can be set to startup and shutdown here)  Apple Menu > System Preferences... > Energy Saver pane.
Check the logs; Go to Macintosh HD > Applications > Utilities > Console. In here (assuming you can get it to stay on long enough to look) you can inspect the various system logs to see what may be causing the power cycling. Each system event is recorded against the time it occurred so you can do some detective work.
Did you leave the iMac unplugged for those two weeks?
Does the iMac take longer than normal to boot up at this time?
Do you get a report saying "Your computer did not shut down properly"?
cheers
mrtotes

Similar Messages

  • Time Capsule HDD keeps cycling on and off while my Mac is sleeping

    Hi guys, I'm in a bit of a hurry so just gonna post dot points:
    • My Time Capsule's HDD keeps cycling on and off continuously and potentially doing heaps of damage to it's drive when my MacBook is sleeping.
    • Time Machine is set to automatically backup to my time capsule.
    • As soon as I wake up and log into my MacBook it seems to stop. I checked the time capsule icon immediately and it says "Preparing backup" so I assume it was stuck in that phrase.
    • I assume it backs up normally after waking up
    MacBook Pro Retina:
    • I usually never put my MacBook to sleep by closing the screen, so can't say if this happens when it's in closed screen sleep vs open screened sleep
    • I'm not sure if there's any difference between close screen sleep and open screen sleep
    • It is set to go to sleep automatically after 45mins of inactivity
    • My iTunes Library is stored off-device on a 2TB HDD connected to the Time Capsule
    Cheers,
    Tony

    How old is the TC and on what firmware?
    You have put Mountain Lion for OS.. is that still the case or upgraded to Mavericks??
    There has been some issues at various times with disk spinning up ..
    This thread might give you some clues.
    https://discussions.apple.com/thread/4148904?start=0&tstart=0
    Is the computer set to power nap? Try turning that off.
    Try unplugging the external drive with itunes library and see if that helps.
    If it is TM the attempts to start the backup should be in the log.
    See A1 pondini troubleshooting.
    http://pondini.org/TM/Troubleshooting.html
    Power nap.. try unplugging the laptop from power.
    http://support.apple.com/kb/ht5394

  • IPad (3rd gen) Wi-Fi which keeps cycling on and off.

    I have a iPad (3rd gen) Wi-Fi which keeps cycling on and off. 

    Please tell me that it has NEVER been jailbroke.  If it has not been jailbroke, here are some standard repair procedures:
    First, try a system reset.  It cures many ills and it's quick, easy and harmless...
    Hold down the on/off switch and the Home button simultaneously until you see the Apple logo.  Ignore the "Slide to power off" text if it appears.  You will not lose any apps, data, music, movies, settings, etc.
    If the Reset doesn't work, try a Restore.  Note that it's nowhere near as quick as a Reset.  It could take well over an hour!  Connect via cable to the computer that you use for sync.  From iTunes, select the iPad/iPod and then select the Summary tab.  Follow the on-screen directions for Restore and be sure to say "yes" to the backup.  You will be warned that all data (apps, music, movies, etc.) will be erased but, as the Restore finishes, you will be asked if you wish the contents of the backup to be copied to the iPad/iPod.  Again, say "yes."
    At the end of the basic Restore, you will be asked if you wish to sync the iPad/iPod.  As before, say "yes."  Note that that sync selection will disappear and the Restore will end if you do not respond within a reasonable time.  If that happens, only the apps that are part of the IOS will appear on your device.  Corrective action is simple -  choose manual "Sync" from the bottom right of iTunes.
    If you're unable to do the Restore (or it doesn't help), go into Recovery Mode per the instructions here.  You WILL lose all of your data (game scores, etc,) but, for the most part, you can redownload apps and music without being charged again.  Also, if you have IOS-7, read this.

  • WRT54GL broadcast keeps cycling on and off

    I've had a WRT54GL ( for about a week now ) with no real issues.  Today my wife mentioned that the net's been flaky  ( wireless nto hard wired ).  I originally noticed what seemed like minutes for my desktop of laptop to connect to any web pages.  Loads were extremely slow.  According to the computer I had a 1 mbps connection.  I did the standard resetting of the modem and router..babble babble babble.  Of course all of which didn't help.
    Eventually, I ran a wifi analyzer from my phone to determine an ideal channel.  However, while running the frequency scanner I also noticed that my broadcasting would continue to drop off the radar for a quick moment then return.  This seemed to be true no matter what channel I set.  What's interesting is that the signal would read as extremely strong for 45 sec - 1 minute, then completely drop the signal, then another strong broadcast.
    Other neighboring signals don't exhibit this behavior....well I would see the weaker signals coming in and off the radar from time to time.
    Has anyone seen anything like this before?  I'm guessing it's some type of interference?  However if that's the case I can't explain why my signal seems so strong.  I'm assuming I'd see a lot of fluctuation in my signal before dropping off ( instead of going from 100 to 0 in the blink of an eye ).

    Connect one computer wired with the router and let me know the IP address from the Router… You can check the IP address in the following manner:
    If you wish to find out your own IP address, you should run the same ms-dos prompt by clicking Start -> All Programs -> Accessories -> Command Prompt. A black pop up box should come up, type: "ipconfig /all" … There check the IP address and Default Gateway under LAN….
    You can try out the following steps:
    # Open up the browser and on the address bar type “Default Gateway” that will open up the Router setup page…
    # Then Click on wireless Tab and select you can make Standard Channel to 6, 9, 11... Click Save Settings...
    # Then click on Advanced Wireless Settings, change Beacon Interval to 75, Fragmentation Threshold to 2306, and RTS Threshold to 2307...
    # Avoid using cordless phones, microwave ovens nearer to the Router…
    Then check the connectivity….

  • Fans Constantly Cycling On and Off

    About a week ago the fans on my dual 2.0 G5 running 10.4.8 started cycling on and off. After a few days of this I ran AHT and received the following error:
    Error Code 2STH/1/2:CPUA AD7417 AD1.
    I found out this was a possible problem with the logic board and immediately took it in to the local Apple authorised repair center. They tested it and found a Thermometer failure on CPUA AD7417. They removed both processors, reset the logic board,reinstalled the processors, and completed calibration. After which they ran ADT test and Apple G5 Service test disk twice. According to them the G5 passed all the tests and had no problems.
    After I got home and set it back up the fans started cycling on and off just as they did before I took it in for repairs–they cycle on and off regardless of the ambient temperature or the amount of work the processors are performing. I ran AHT's extended test which it passed with no problems.
    What's going on? Did they mess up when they were doing the calibration? Am I going to have the same problems that prompted me to take it in for repairs to begin with? Is there a serious hardware problem that they failed to discover?
    The service was poor, and they even managed to scratch the **** out of the side of my G5, so I don't really want to take it back to them again. Unfortunately the closest Apple Store is about 4 hours away and my G5 is no longer under warranty.
    Any suggestions about what's causing the problem and what I should do would be really appreciated. Thanks.

    Blinn–
    Nope, I hadn't installed a software update. It just came out of nowhere. If you haven't done so, I reccommend running AHT to see what it shows. Hopefully you're just having a software problem.
    DaddyPaycheck–
    Thanks. That clears it up. I am definitely going to call Apple. I am really fuming about the lack of service I've had from the "Authorised Repair Center."
    UPDATE
    It just keeps getting worse. Now the G5's fans are really revving up and it is putting itself to sleep with increasing frequency. I just got off the phone with the guy who "repaired" it. The reason that AHT is showing the same error code, but on processor B is because when he reinstalled the processors after resetting the logic board he switched them. According to him, this error shows that it is a problem with processor B, which will need to be replaced. It's going to cost $581 for the CPU–no charge for labour since I've already paid to have it fixed once even though it wasn't!–but I don't think I want anyone at that shop working on it again.
    Has anyone else replaced a CPU in a dual 2.0 G5? How much did it cost you? Is this something that I could do myself?
    I think that before I do anything else I'm going to take DaddyPaycheck's advice and call Apple. At least then Apple will know that this authorised repair center is doing a terrible job!

  • Airport cycling on and off repeatedly

    I have a time capsule purchased March 2008. The updates are current. Had no problems until the last 2-3 days. Now, it is cycling on and off. It will not stay connected to the internet. The light goes from green to yellow to off to yellow to green. I have shut everything off, unplugged the time capsule, the DSL, ran the disk repair utility.
    There are no clicking noises. When it is working with the green light, all seems well but it keeps shutting down.
    Is it broke? Software problem?

    Will I loose all my backups when the power completely fails? It is a 2 terrabyte hard drive and I have it full with 2 machines backed up on it.
    The data should not be affected as it is stored on the internal hard drive ... which (push comes to shove) can be removed. One thing you can do, is if you have another USB drive handy is to perform a data archive to add some additional "insurance." You have been doing these all along, haven't you?
    I can get the Apple store to put a new power supply? Or should I buy a new time capsule?
    There are no replaceable parts that I am aware that Apple will perform on the TC, but it would be a good idea to have the Apple Technician give the TC a good look at to verify if even the power supply is an issue in the first place.

  • HT1695 my phone keeps cutting on and off wat should i do

    my phone keeps cuttin on and off wat should i do

        @BrandiCe
    I can imagine this has become a frustrating experience for you!  I would love to assist with resolving this wireless issue for you.
    When did this problem begin?  Had you recently installed any new applications or recently updated your device software?  How often does your device power cycle?  Is it happening when performing any specific tasks on your device?  Please let me know so that I can further assist.  Thanks!
    AnthonyTa_VZW
    Follow us on Twitter @VZWSupport

  • My Galaxy 4 keeps turning on and off by itself and the battery gets pretty warm

    I have a Galaxy S4 and it keeps turning on and off by itself.  As well the battery usage is pretty quick and the battery keeps getting pretty warm.  Any thoughts.

    Thanks to all of you for your input. Fortunately, for me, the phone was still under warranty so there's no expense to me.  However, during the course of my conversation with the Tier 2 tech, it was mentioned that a recent update MAY have been the problem.  But after doing a refresh, the problem continued with the phone turning on and off all by itself.  That was the whole problem.  But, the battery life went down dramatically within a few hours after it had been charged all night.  I was told that this was due to the phone cycling and off.  As well, even the safe mode didn't solve the problem that would allow me to use the phone without being able to use the apps.  I had pulled the battery to let it set for a while but with no success.  I also pulled the SIM card before they refreshed the update but, still no go.  Anyhow, the end result was that the Tech that I was talking to then transferred me to another Tech -- I guess someone a little higher up -- and I was then informed that they were going to send me another phone.  I don't recall that anyone placed the blame on Samsung or Verizon.  So, there ya go.  Thanks again.

  • The power button on my iPad mini is stuck in so iPad just keeps turning on and off

    The power button on my iPad mini is stuck in so iPad just keeps turning on and off! How much would it cost to fix?

    Hey Tommy_mccloud!
    I have a link for you that can help you find the answer to that question:
    Apple - Support - Service Answer Center
    http://support.apple.com/kb/index?page=servicefaq&geo=United_States&product=ipad
    Take care, and thanks for visiting the Apple Support Communities.
    -Braden

  • My ipod got wet and now it keeps turning on and off.

    i got my ipod wet and now it doesn't even have enough power to charge. it just keeps turning on and off

    - Yes. Restoring the iPod erases the iPod.
    - Try a reset to:
    Reset iPod touch: Hold down the On/Off button and the Home button at the same time for at
    least ten seconds, until the Apple logo appears.
    - Try placing the iPod in Recovery mode and then restoring
    - Next try DFU mode
    How to put iPod touch / iPhone into DFU mode « Karthik's scribblings
    - If you can't turn it off, let the battery fully drain. After charging for  at least an hour try again.

  • Phone cycles on and off.  I have restored and so has the apple store.

    I had a screen sensitivity issue with my original 4s.  It would react to my finger getting within about 1/4 inch of the screen, and would auto dial without anyone touching the screen.  Fortunately, It happened to actually do this in front of one of the 'geniuses' on my third trip to the apple store so they replaced the phone about 5 months ago.  I was given a 90 day warranty on the new phone.  It worked fine until last week.
    It started cycling on and off.  Then it wiped the phone and all of my apps.  I restored the phone but there would be a noticeable hesitation between when I touched the screen and when the touch registered.  This went on for two days.During those two days the power indicator did not ever show any indication there had been any battery drain, but always showed 100% charged, days, then went dead without ever showing it was discharging.  I took it to the Apple store.  They tried to do the same restore I had.  The phone came back on, but then cuts on and off to the Apple logo.  The battery will take a charge, but as it sits on the charger it cuts on and off.  The store solution was for me to purchase a new phone since they either had no idea what the problem was, or wouldn't tell me.  The phone has not had rough treatment or been exposed to water or excessive moisture.   Any suggestions?

    try to force restore using: http://support.apple.com/kb/ht1808
    If that doesn't work, I'm afraid the device needs another hardware repair.
    Please note that using that article will erase everything so make sure you've got a backup.
    But restore it AS NEW if it's at all possible.
    Good luck
    Stijn

  • MSI X99S Xpower AC Cycles on and Off

    My rig has been stable for the past month (please refer to footer for components) and today it started to just cycle on and off in approximately 5 -10 second intervals.  I downloaded and updated my bios 30 days ago, and it has been very stable.  I also verified the BIOS settings today to make sure they were OK.  However, today it just started to cycle on and off.  When this occurs, the power supply is also powering on and off which may be the culprit.  Could the power supply be going into hibernation with the CPU I have?  Not sure how if it has been working fine.  I also do not overclock at this time.  Any suggestions on what to try?

    Not sure how concerned I should be, however, yesterday when I was going to perform the tasks posted by pandaz, as well as perform the paper clip test on the power supply (this verifies the integrity of the power supply by taking the MOBO out of the equation), the issue did not reoccur from the previous day (it was off all night, but still plugged in).  The first time this happened (shortly after building my rig about two months ago), simply clearing the CMOS took care of the issue (in review of my notes), and this time, clearing the CMOS did not, however, letting it sit overnight did.  Do I have an issue I need to be concerned about?  My legacy XPower Big Bang never had any issues after setting it up a few years ago.  Thoughts?

  • My ipod keeps flashing on and off

    My IPOD keeps flashing on and off how do i fix it

    Try:
    - iOS: Not responding or does not turn on
    - Also try DFU mode after try recovery mode
    How to put iPod touch / iPhone into DFU mode « Karthik's scribblings
    - If not successful and you can't fully turn the iOS device fully off, let the battery fully drain. After charging for an least an hour try the above again.
    - If still not successful that usually indicates a hardware problem and an appointment at the Genius Bar of an Apple store is in order.
      Apple Retail Store - Genius Bar

  • Droid Pro Cycling On and Off

    My brand new Droid Pro keeps going on and off.  Bought it yesterday, can't get it to stop.  Suggestions please before I return to store?

    Take it back and exchange it. This is an issue with the Droid Pro. Some are worse than others. Mine does this about once a week, but others have had this happen several times a day. Every Verizon employee I have talked to insists it's either an app you installed that is doing it, or just a reset that will fix it. Neither are true, as people (including me) have had the problem even after totally resetting the phont to factory default with no additional apps installed. When I called them after owning the phone for a week, they said they would need to prove in the store that it was an issue before exchanging it for me. I said, how can anyone prove this if it happens only about once a week. He said "sorry, that's the best I can do." I should have insisted they take it back!

  • [59-429213] LTE Modem keeps swithcing on and off every 30seconds

    I recently bought Lenovo Yoga 2 with Windows 8.1. Everything works great except lte modem. It keeps switching on and off every time I am using the internet connection. When tablet is resting, then modem is working, but when I'm trying to do something, browse the web for example, it starts to freak out. Modem disappears from Device Manager for couple of seconds and keeps on popping on again after 3-5 seconds. Then it tries to connect to the provider, then I've got the internet connection for about 30 seconds and the same thing all over again. Modem disappears from device manager, opening on again after 5 seconds and tries to reconnect (with success) with the provider and so on, and off, and on, and off. It is very frustrating and I tried to find some solution but unfortunately without success. Maybe you guys will have any idea what is going on. Thanks in advance.

    You have to update the EM7345 firmware. What version do you have now ?
    More info here http://forums.lenovo.com/t5/ThinkPad-Tablets/Sierra-Wireless-EM7345-ThinkPad-8-and-10-general-issues...

Maybe you are looking for