I had to take it in store, they took it for a couple days and it worked for about a week before it started shutting down again
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27" iMac shuts self down and will not turn on unless unplugged first
- Thread starter JordanKyle94
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I had to take it in store, they took it for a couple days and it worked for about a week before it started shutting down again
This is happening to me and I just started using a new USB hub. How is it causing the comp to shut down?
Just in case it helps anybody else, I've been having this same issue for months. My computer is a late 2012 iMac 27" running OSX 10.13.1 and it will go completely black and be unresponsive to any inputs, including the power button, until the cord is unplugged for at least 10-15 seconds and put back in.
I spent a couple months testing it and found that it never has the issue when I have only the thunderbolt plugged in. I would keep an external monitor plugged into one of them for a couple weeks and the error would never occur. Then, I started testing the USB ports individually and one by one 3 out of the 4 have had the issue. I'm now testing the 4th and I expect it will occur there eventually. USB port #3 took a few weeks to fail, which was surprising, but finally did it tonight after an update. Thankfully it didn't seem to happen during the update at least.
It drives me nuts, but I suppose I could perhaps figure out a workaround by having a thunderbolt to USB adapter. I'm currently testing the last USB with a wired apple keyboard, and have tested the other ports with a bluetooth mouse/keyboard dongle.
I've looked elsewhere for any info on this and had seen people saying that it had something to do with USB, which is what led me to this attempt at troubleshooting. I'm skeptical that apple would be able to help much from what I've read and the experience I had with support already. And since I bought this machine used and it's 5 years old, it's likely not worth dropping a significant chunk of change on a repair if I can do the thunderbolt to USB workaround.
Ugh, so annoying. Anyway, perhaps that'll help someone else with diagnosing this issue.
I spent a couple months testing it and found that it never has the issue when I have only the thunderbolt plugged in. I would keep an external monitor plugged into one of them for a couple weeks and the error would never occur. Then, I started testing the USB ports individually and one by one 3 out of the 4 have had the issue. I'm now testing the 4th and I expect it will occur there eventually. USB port #3 took a few weeks to fail, which was surprising, but finally did it tonight after an update. Thankfully it didn't seem to happen during the update at least.
It drives me nuts, but I suppose I could perhaps figure out a workaround by having a thunderbolt to USB adapter. I'm currently testing the last USB with a wired apple keyboard, and have tested the other ports with a bluetooth mouse/keyboard dongle.
I've looked elsewhere for any info on this and had seen people saying that it had something to do with USB, which is what led me to this attempt at troubleshooting. I'm skeptical that apple would be able to help much from what I've read and the experience I had with support already. And since I bought this machine used and it's 5 years old, it's likely not worth dropping a significant chunk of change on a repair if I can do the thunderbolt to USB workaround.
Ugh, so annoying. Anyway, perhaps that'll help someone else with diagnosing this issue.
Clarification: I would have only one thunderbolt port being used, and for one external monitor, when doing that testing. None of the USB ports would be engaged because I wanted to go port by port to try to single out where the problem might be happening.
So when I had only one thing plugged into the machine in the thunderbolt ports (either of them), the crashes did not occur. But once I had one thing plugged into a USB port, the crashes would occur. Currently on the 4th and final USB port for the last day and it has not died yet, but sometimes it takes days or weeks before it happens.
Sounds like an IO card/bus failure. I've seen that recently. Looks like a kernel panic, but eventually, I could not even boot into recovery mode without it crashing. If it required to be unplugged before it would power on...that sounds like th 2007 iMac power board failure I had.
These symptoms are 95% caused by a failing power supply.
Suddenly power off, will not power on unless you first unplug it for a bit.
I have seen it several times at our shop, you need to take it to an AASP for a replacement power supply.
Suddenly power off, will not power on unless you first unplug it for a bit.
I have seen it several times at our shop, you need to take it to an AASP for a replacement power supply.
So, I've been issues with mine dying and I'm pretty sure it's the power supply. I found a thread regarding the green LEDs that should be there when there is wall power applied (look through the vents near the Apple logo). Interestingly, when mine randomly shuts down - those LEDs go out.
Just curious - occams_blazer - have you seen the same? Next time it dies, see if you can see those LEDs...
Anyone have any further information on that?
Just curious - occams_blazer - have you seen the same? Next time it dies, see if you can see those LEDs...
Anyone have any further information on that?
That's a good tip, thanks. Sorry for the delay in responding. I'm not sure why I wasn't getting email notifications about further replies, so I only saw these after visiting to give another update.
Update on the situation:
I bought a Belkin thunderbolt 2 dock to see if using the USB ports in there would cause the same issue to happen. Yesterday I finally got a thunderbolt 2 cable (figured out the hard way that mini displayport doesn't work) hooked it all up, and it seems solid. I currently have multiple USB devices and cables plugged into the dock, which is plugged into the iMac via the thunderbolt 2 cable.
It's been plugged in for only ~15 hours or so, but I'm really heartened by this. I'm finally able to use USB on my desktop and I didn't need to take it in for expensive servicing!
In case you're curious, I managed to find the dock relatively cheap and used on ebay for ~$80 CAD. I wasted $15 on the mini displayport cable and then found a thunderbolt 2 at work. I'll update if it crashes again, and if it does so I'll look for the LEDs.
This is the item: http://www.iphonecaptain.com/belkin-announces-thunderbolt-2-express-dock-hd-apples-macs/
It has a really sturdy power supply that can output up to (I believe) 6 amps. It's meant to be able to daisy chain multiple other docks and monitors, as well as a variety of other peripherals. The problems occurred when any single item was plugged into the imac and the dock is the solution to the problem.
It has a really sturdy power supply that can output up to (I believe) 6 amps. It's meant to be able to daisy chain multiple other docks and monitors, as well as a variety of other peripherals. The problems occurred when any single item was plugged into the imac and the dock is the solution to the problem.
So, I wanted to swap out the HDD for an SSD so I broke open the iMac. While in there, I went ahead and swapped out the power supply. 4 days later and it's still running. I've been using it pretty regularly and trying to load it up. So far, so good..
Most off the problems is cause by the capacitors of the PSU unit are loosing the capacity to filter. Any peak or variation of input supply can cause this behavior.
One time I had a hp computer with the same problem and at the repair store all working for a week, came to home same problem. The store have a UPS, bought one and problem solved.
After a while only because I wanted bought new power supply and repair the old one. Now the computer have the repaired one and heaven connect directly to source run fine.
One time I had a hp computer with the same problem and at the repair store all working for a week, came to home same problem. The store have a UPS, bought one and problem solved.
After a while only because I wanted bought new power supply and repair the old one. Now the computer have the repaired one and heaven connect directly to source run fine.
I've been having a very similar problem. My 2012 iMac randomly switches off and I have to wait 5+ minutes before I plug it back in — it then switches on automatically without having to press the power button!
Cheers!
Have you had any problems since posting this?
Cheers!
No problems to date and it's been 16 days (not that I'm counting.. ha).. but we are using it pretty much all day every day and have not had a single issue. So, I think I'm good because it hasn't run that long for at least a year...
Good Luck!
I had same problem a year ago and having same thing now and it seem to be a common issue with this machine I'm sorry to say it is the power supply don't let Apple sell you down the road with logic boards fans an hard-drives replace it yourself its not hard the power supply is $100-117 depending were you live follow instructions on tube video it will take 1 to two hours but a lot cheaper than $400- $700 dollars.
I've had this problem for over a year, initially Apple blamed their beta software which ultimately fried my power supply with continually pulling the plug out, this was replaced but the problem has returned.
I've got rid of the beta software on their advice and the iMac continues to just switch off, now have to wait 10 days until I can get it into a store.
I've got rid of the beta software on their advice and the iMac continues to just switch off, now have to wait 10 days until I can get it into a store.
Update from me, my iMac has been in for repair twice, one the power supply was changed, the second time the logic board was changed. Tested in the workshop and cleared to come back, only they didn't realise they left a stick of RAM lose, good job somebody checked.
Within a week I've got the same problems, power just cutting out, no crash reports, usually happens when using resource hungry software. iMac now going back to see if it will crash for them, replacement agreed if it will.
Within a week I've got the same problems, power just cutting out, no crash reports, usually happens when using resource hungry software. iMac now going back to see if it will crash for them, replacement agreed if it will.
I had a similar issue where my screen would go black and I would have to restart. They replaced the Logic Board, but it happened again a week or two later. Next time they replaced the Logic Board and the fan. Turned out the fan was defective and not cooling the board.
I'm having exactly the same issue with my 2015 27" iMac.
They replaced the logic board last October due to graphical issues.
It started cutting out in March, they tested it for a couple of hours and decided to just re-install the OS.
It's going back in for repair because their solution didn't work.
They replaced the logic board last October due to graphical issues.
It started cutting out in March, they tested it for a couple of hours and decided to just re-install the OS.
It's going back in for repair because their solution didn't work.
