1 2 Previous Next 22 Replies Latest reply: Oct 3, 2006 5:59 PM by MGW
AShepherd Level 1 Level 1 (0 points)
Over the last few days my iMac has taken to shutting down unexpectedly, even if I'm in the middle of doing something on it at the time.
It's not in sleep mode, it's off completely, as if the power had been pulled.

If I switch it on again, it comes on as usual. If I set the Power Saving settings so as to come back on again after power loss, it will automatically come back on after this unprompted shutdown.

I've reset the SMU, PRAM and NVRAM, verified and repaired permissions, done the full hardware test (which reported no problems), and it still happened again earlier today!
The only thing I've not tried is a verify disk and repair disk, as I need to make a backup first just in case and haven't had time lately. Then leaving it on overnight with the system disk in to see if it still shuts off.

In the logs, I see an AppleSMU message with shutdown cause -122 or -110.

It's not covered by the power supply support extension programme, as it's a 2nd generation G5 iMac (2Ghz, ALS), which has not had any hardware modifications.

It's going to be a pain to take it in to an Apple Store, so I'm trying to cover everything possible before resorting to that, especially as the fault is intermittent (didn't happen at all on Saturday) and may not happen at all if I take it in!

Thanks in advance for any further advice, and I'd like to hear if anyone else has had a similar problem and how they resolved it!




iMac G5 (2.0Ghz)   Mac OS X (10.4.7)  
  • 1. Re: Sudden Shutdowns
    AShepherd Level 1 Level 1 (0 points)
    Ah. Actually, on closer looking, my serial number does fall within the range:-
    W8435xxxxxx - W8522xxxxxx
    named here:-
    http://www.apple.com/support/imac/repairextensionprogram/

    So looks like a trip to the Apple Store, then. Bah!
  • 2. Re: Sudden Shutdowns
    MGW Level 7 Level 7 (27,000 points)
    The problems with the PSU are mostly with the RevA machines, but they are not entirely limited to them. Your abrupt shutting down sounds very much like the same problem. Have you checked your console logs to see if there is anything in there about "temperature exceeded for longer than 30 seconds"? Hopefully, you are still covered by your warranty, and if so, please get AppleCare before it runs out.

    Do post back with results,

    Miriam
  • 3. Re: Sudden Shutdowns
    Charles Minow Level 6 Level 6 (9,190 points)
    Hi--

    In the logs, I see an AppleSMU message with shutdown
    cause -122 or -110.


    Thanks in advance for any further advice, and I'd
    like to hear if anyone else has had a similar problem
    and how they resolved it!


    This sure sounds like the Power Supply problem, which is a known problem for certain models of the iMac G5, complete with those log messages. Unfortunately, the techs at the Apple Store aren't given those codes, so they don't mean anything to them.

    I had to make two trips to the Apple Store with my iMac earlier this year. The first time, they couldn't get it to fail, so they wouldn't take it. Within a couple of days, though, it wouldn't start up right away, either from a clean shutdown or one of the unexpected ones. I'd have to let it sit for a while before I could power up again. So I took it back, and even though it wouldn't shut off "unexpectedly" doing the iTunes test (see below), when they tried to start again to run or remove their diagnostic CD, and it wouldn't power up, that sold them. They took it in then.

    One way they test it is to open up iTunes, turn on the full screen visual effects, and let it play. Once they replaced the PSU on mine, I had one song in iTunes with 230 plays! Running iTunes like that stresses the computer pretty thoroughly. The CPU has a pretty constant load, there's some disk activity going on, and the graphics card gets some good use from the visual effects. And the fans will ramp up, which puts more load on the PSU...

    charlie
  • 4. Re: Sudden Shutdowns
    AShepherd Level 1 Level 1 (0 points)
    OK. Everything was pointing to the power supply as being the source of my problems, so rather than having to book an appointment and drag it out to the nearest Apple Store, I ordered a replacement power supply unit and changed it myself.

    Since then, I've had it on for as long as 20 hours and have not had a reoccurrence of the problem.
  • 5. Re: Sudden Shutdowns
    MGW Level 7 Level 7 (27,000 points)
    I am very glad that you posted back and confirmed my diagnosis of PSU failure. If you feel that any of the above posters was helpful, you can award stars, a green one for solved, and two yellow ones for helpful.

    Miriam
  • 6. Re: Sudden Shutdowns
    phil_butler Level 1 Level 1 (0 points)
    I am glad to see I am not the only one with the iMac shutdown problem. I have a summer 2005 20" model (the one before the iSight version)(for 13 months) and it's been working perfectly till about 2 weeks ago. It'll go along and suddenly shutdown - sometimes several times in a few minutes. Sometimes it'll go for hours and hours without a problem. Fortunately, I have AppleCare on it, so as soon as my 24" iMac shows up, I am going to send it in.

    My question is - is it better to send it in or to call Applecare and replace the power supply myself. I have no problems opening it up and following instructions.

    Thanks,

    Phil
  • 7. Re: Sudden Shutdowns
    Bryce Jacobson Level 1 Level 1 (0 points)
    We're having the same problems on a work iMac Second Gen 2.0 GHz. We took it to the nearest Apple repair shop but they weren't able to recreate the problem. The iMac went out of warranty in May so it doesn't have Apple Care on it. The serial number falls into the range of the affected iMacs but being a second gen it isn't covered. What would be our best way of getting this fixed. I could replace the power supply myself but its my understanding that they won't send us one unless its been verified by technician. Any advice would be grateful.

    iMac 2nd Gen 2.0 Ghz G5   Mac OS X (10.4.7)  
  • 8. Re: Sudden Shutdowns
    Charles Minow Level 6 Level 6 (9,190 points)
    Hi--

    I could replace the power supply
    myself but its my understanding that they won't send
    us one unless its been verified by technician.


    You should try to get them to send you a power supply. We had a G5 tower at work that was doing the shutdown. Of course, the repair tech couldn't get it to fail when he had it. I know it took some negotiation but we finally got them to sell us a power supply. You might have to escalate your case to someone else besides the technician, though I don't know how to do that.

    Any
    advice would be grateful.


    In the case of my iMac G5, the problem gradually got worse, so it might just be a case of waiting a bit and taking it in again, which is a drag, I know.

    One thing I discovered with mine was that eventually, the iMac wouldn't restart right away. It had to cool down for about a half hour before it would restart. I could easily repeat it (and therefore demonstrate it to the techs) by firing up iTunes and turning on the full screen effects. After about 15 minutes, even if the iMac didn't shut off on its own, if I shut it down, I couldn't restart right away. That was proof enough for them to replace the PSU under the repair program.

    charlie
  • 9. Re: Sudden Shutdowns
    DLF Level 3 Level 3 (510 points)
    Well, sadly, unfortunately, and expensively, my son is yet another victim of a G5 iMac Rev B with a bad PSU, just out of warranty, no Applecare, right serial number for repair extension program, THAT IS NOT COVERERD!

    A phone conversation today with Customer Relations proved to be a complete waste of time. They refused to step up and recognize that this issue (that was SO PREVALENT on the Rev A's that Apple FINALLY instituted the warranty extension program on February 11, 2006) may be affecting a number of Rev B machines as well, if you believe many of the posters on these and other forums.

    As it was explained to me, Apple claims the PSU for the Rev B was redesigned and is completely different from those that failed on the Rev A. I have my doubts. I ordered the Rev B for my son the first week they were announced (I followed the Rev A horror stories posted here and thought it was safe to proceed...) and stupidly did not get Applecare for the machine. His random, sudden shutdown symptoms started about 11 months after he registered his computer. He was in the middle of finals as a freshmen in college, and couldn't deal with it until he came home for summer break. Unfortunately, it was too late.

    I fully recognize that computers are rarely perfect in their design and are fallible, but these notorious PSU incidents are so eerily similar that I cannot help but conclude that at least some of those bad Rev A power supply units made it into the early runs of the Rev B. It is a theory as I have no tangible evidence, and Apple denies that is the case, but common sense dictates otherwise.

    As a longtime, devoted Apple fan from the days of the IIc, needless to say, I am now an extremely disappointed customer. My only recourse is to follow up with a formal letter expressing my thoughts on this matter to the powers that be in Cupertino.


    20 iMac G4 1.25ghz   Mac OS X (10.4.7)   1GB Ram, External FW Drive, iSub, Wireless Microsoft mouse, 30GB Black Video Pod
  • 10. Re: Sudden Shutdowns
    Bryce Jacobson Level 1 Level 1 (0 points)
    I just got off the phone with Customer Service and they were nice enough to talk to me even without having Apple Care at the moment. I told them the problem and they didn't really ask questions about it I just said I would like new PSU and I could install it myself. After looking stuff up and they pointed me to this page http://docs.info.apple.com/article.html?artnum=86812 which states: Note: Although the power supply for original iMac G5 models was available as a standalone DIY part, these items are no longer available as part of the DIY program to ensure the highest quality repair experience for our customers. For more information, see the iMac G5 Repair Extension Program for Video and Power Issues. That ruled out getting a PSU from Apple to put in myself.

    Its now down to waiting for the computers problems to get worse and taking another shot at bringing it to the repair shop to see if they can finally acknowledge the problem. But the $49 we paid the first time with no results makes me not want to bring it back and/or make them refund it if it happens again.

    Just a heads up for others with the same problems.
  • 11. Re: Sudden Shutdowns
    backyard1 Level 1 Level 1 (0 points)
    I am more or less in the same boat as the previous poster, though I did have a slightly nicer experience with the second tech support person I spoke to. My intermittent shut-downs are as described by everyone else here. I have a RevB purchased in August of 2005 and, wouldn't you just know it, it started the shutting down thing about a month and half out of warranty. People PLEASE BUY THE EXTENDED WARRANTY if you decide to buy these machines. They have problems that will be expensive to fix without the warranty!

    My machine did not fall within the range for the replacement scheme on the power supply even though that is what is wrong with it. The best they could do for me was sell me a new power supply for US $115.00 and help me troubleshoot for free to make sure that the power supply definitely WAS the problem (they examined the crash logs which I sent them). That was nice of them. Paying $49 to find out your computer is essentially defective is insult to injury and they know it. Anyway, my new power supply is on its way and I am assured it is easy to swap out. They gave me 90 days return on the part if does not fix the problem but told me I would have to bring the mac into the store for any further hardware troublshooting.

    BTW this iMac was a replacement. The first one I brought home had unsolvable hardware issues and was replaced by a new machine when the genius bar could not solve the haunting, intermittent crash issue the first one had.

    My last Mac, ever. I swear it. Devoted customer for over 20 years too. These machines are getting prettier and crappier year by year.

    imac G5 20"   Mac OS X (10.4.7)  
  • 12. Re: Sudden Shutdowns
    Washu Level 1 Level 1 (0 points)
    I had the same problem with my 2nd gen iMac G5. It was one of the first shipments in the Bethesda MD, apple store. Of course the problem started 3 months out of warranty. My sister is having the same problems with her 2nd gen iMac. In her case the power supply may have damaged the motherboard and hard disk drive

    I was able to convince the apple support to send me a power supply for $111 ($115 - I guess is an estimate with shipping costs). I paid for the iMac with a credit card that extends the warranty for a year, so the cost is covered.

    It was a pain to replace. It looks like it should pull straight out, but you have to pull it out at an angle. The middle screw was catching on the iMac screw hole and the power supply housing, which made things difficult. Some of the capacitors were close the power supply, so I had to be careful not to bend them too much when installing the new power supply.

    The serial number of the new power supply is lower than the old one, but it works so far (about a week).


    G3 iMacs, G5 iMac, MacBook Pro, 1st gen iBooks, etc   Mac OS X (10.4.7)  
  • 13. Re: Sudden Shutdowns
    KathyN Level 1 Level 1 (20 points)
    I had the same problem with my 2nd gen iMac G5. It
    was one of the first shipments in the Bethesda MD,
    apple store. Of course the problem started 3 months
    out of warranty. My sister is having the same
    problems with her 2nd gen iMac. In her case the power
    supply may have damaged the motherboard and hard disk
    drive

    I was able to convince the apple support to send me a
    power supply for $111 ($115 - I guess is an estimate
    with shipping costs). I paid for the iMac with a
    credit card that extends the warranty for a year, so
    the cost is covered.

    It was a pain to replace. It looks like it should
    pull straight out, but you have to pull it out at an
    angle. The middle screw was catching on the iMac
    screw hole and the power supply housing, which made
    things difficult. Some of the capacitors were close
    the power supply, so I had to be careful not to bend
    them too much when installing the new


    Washu, I take comfort in your post as I took my 2nd Gen iMac G5 in for repair instead of trying it myself and have to pay $264 for them to install a new power supply. Doing it myself may have saved me some $, but on the other hand, doesn't sound as easy as installing RAM so I could have easily damaged something.

    But you said you paid for the iMac with a credit card and that EXTENDS the warranty for a year? I paid with a credit card, too. How do I access this benefit? Who will pay you, the CC company? I spoke to Apple today and KNOW it's not going to be them! This brings a little hope to my outrage at Apple for all the reasons being spouted on the threads dealing with the failed power supply that is known but not being covered by Apple....

    I'm kind of amazed that so many of us had it happen this week...just a few months out of warranty...
  • 14. Re: Sudden Shutdowns
    MGW Level 7 Level 7 (27,000 points)

    But you said you paid for the iMac with a credit card and that EXTENDS the warranty for a year? I paid with a credit card, too. How do I access this benefit? Who will pay you, the CC company?




    You need to have a receipt or proof of payment, then contact your cc company and they will tell you how to submit a claim. I have done this with Amex more than once, but I think Visa et al do the same.

    Good luck,

    Miriam
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