iMac won't start up after power outage - lost cause?

Discussion in 'Mac Basics and Help' started by Philip S, Jan 7, 2015.

  1. Philip S macrumors newbie

    Mar 21, 2014
    Is Weaselboy still active on this page? He saved my bacon twice with solid advice (once in relation to retrieving data from a non-formatted external hard drive and once concerning the replacement of my Mac's graphics card), so I value his feedback and trust his judgement.

    I have a new Mac problem, which doesn't seem all that rare going by a google search, but opinions vary widely about solutions so I figured this is the best place to go.

    On a recent morning I switched on my iMac and just after I heard the power-up chime all electrical power in my apartment suddenly cut off (several things were running at the time, but nothing that unusual - the television, Christmas tree lights, the toaster, maybe the washing machine, I don't recall exactly).

    After flipping the breaker switch everything came back on. Everything, that is, except my Mac.

    Some links in the google search said Macs are sensitive to power surges/outages and, depending on the source, say that either a memory card is blown or the motherboard is fried.

    I have most data backed up on external hard drive, but there was quite a lot of work on the desktop I hadn't backed up yet (stupid, I know).

    I just need to know, is there any chance if saving the computer and retrieving that data? Or if the memory/motherboard is fried does that mean all data is gone with it? Where exactly is data stored?

    My computer is a bit old and way past warranty date, but if it's possible to replace a part myself to get it running again I've no problem doing so.

    I opened it up to (successfully) replace the graphics card before, using solid clear instructions from, plus the card was good and reasonably priced, so I can trust the parts vendor I bought the graphics card from if I need to purchase some part or parts.

    Is it a lost cause, or is there anything I can do?

    The iMac is chipset model ATI Radeon HD 2600 Pro, Processor: 2.66GHz Intel Core 2 Duo running Mac OS 10.5.8
  2. Fishrrman macrumors G5


    Feb 20, 2009
    When you press the power-on button, what happens?


    Or, absolutely nothing?
  3. Weaselboy Moderator


    Staff Member

    Jan 23, 2005
    Hard to say for sure. If you don't get anything action at all when you press the power button, it is most likely the internal power supply that blew out.

    I don't even know how you would test it though and I hate to see you buy a power supply then it ends up being the logic board (which is also possible).

    As a last resort you can open it up and just remove the hard drive and buy a cheap external USB enclosure to put the drive in to access you data on another Mac.
  4. Philip S thread starter macrumors newbie

    Mar 21, 2014
    Nothing at all. No chime, no fan sound. :( I've tried plugging other devices into the same socket and they work fine, so it's not that.

    I seem to remember when I opened it up last time there was a tiny series of diagnostic LEDs which light up when everything is working right.

    Might they provide a clue?


    But, if I buy a new Mac and try what you say (put the old computer's hard drive in a USB enclosure) will I definitely be able to access the current data? iTunes info etc.?
  5. Weaselboy Moderator


    Staff Member

    Jan 23, 2005

    I'm betting those LEDs don't even come one from what you are describing.

    Assuming the power surge did not also kill the hard drive (which is not likely), yes just pop the drive in an enclosure and you can get all your data off easily with another Mac.
  6. old-wiz macrumors G3

    Mar 26, 2008
    West Suburban Boston Ma
    did you have the iMac on a surge protector or ups?
  7. Philip S thread starter macrumors newbie

    Mar 21, 2014
    Unless such a surge protector was built-in to the computer, no, I don't think so.
    I never installed any surge protector myself.
    As far as I remember, there were a few power outages over the last ten years, but this refusal to boot up is a first.
  8. old-wiz macrumors G3

    Mar 26, 2008
    West Suburban Boston Ma
    There's no built in surge protector per se. We have had power surges here, and the last one killed the TV, the Coffee Maker, and maybe one or two other things. Our iMac and Mac mini were fine - they are on a UPS. I also set the Macs to NOT restart after power failure. We now have surge protectors on both TVs.

    Electrical surges are a real threat to electronics - I'd take your iMac to a repair center and have them look at it. It sounds like something blew, but fixing it or diagnosing exactly what is the problem I don't know.
  9. westom, Jan 8, 2015
    Last edited: Jan 8, 2015

    westom macrumors regular

    Nov 8, 2009
    First, nothing in that post describes a surge. A surge is maybe thousands of volts on AC power. You have a circuit breaker trip. That is a blackout. Blackouts do not cause electronics failure. Especially not to a most robust electronic devices in the house - a computer. Ignore urban myths that hype 'sensitive' computers.

    All electronics already contain robust surge protection as defined by industry standards that existed even long before the IBM PC. Spec numbers for computer typically define even more robust internal protection.

    Moving on. First, what caused the circuit breaker to trip? Nothing else? What kind of circuit breaker was it - conventional, RCD, GFCI, AFGI, etc? Something defective on that circuit caused a breaker trip. An important fact.

    If a short inside the computer, then an odor must have been apparent. Something inside the house caused that breaker to trip.

    Computer failure is often only one tiny part - is not massive failures. To say which part means buying or borrowing a simple meter (ie $5 or $12). Requesting instructions, and reading and reporting the resulting three digit numbers. What follows is what is defective without "it could be" or "it might be" expressions. That one minute of labor means spending less money, fixing it the first time, and learning from the event.

    Your other option is shotgunning. Just start replacing good parts until something works. Many on speculation recommend first replacing the power supply. Bottom line. If shotgunning, then your choice of what to replace next is just as good as anyone else’s.

    Your data would be just fine. Parts that cause a power failure do not involve and do not harm disk drives.

    So back to the obvious. If anyone says you had a surge, then you know he has no basic electrical knowledge. Best is to avoid such recommendations.

    A third option - assuming you do not want to fix it yourself and learn how simple this stuff and a meter really is. Take it to the shop. They will find and replace the one defective part.

    Meanwhile, learn what caused that breaker to trip. Very first step in the investigation - what kind of breaker is it?
  10. Blue Fox macrumors 6502a

    Blue Fox

    Apr 13, 2009
    Unplug it from power completely. Disconnect the power cable. Let it sit there all day, and try again tomorrow. I know it sounds odd, but I've come across several newer iMacs that have done this after a power failure, and after a day or so of being completely unplugged with the power cord unplugged as well, they just turned back on as if nothing happened.
  11. westom macrumors regular

    Nov 8, 2009
    It has power lockup protection. That means an AC anomaly causes its power controller to lock out. Disconnecting power for a maximum of 5 seconds resets that safety lockout function.

    After 5 seconds, nothing more changes.
  12. dazzer21 macrumors 6502

    Oct 18, 2005
    What about the power lead itself? Is it fused? If it is, the fuse in that might have blown.
  13. Blue Fox macrumors 6502a

    Blue Fox

    Apr 13, 2009
    Well, doesn't explain what happened to me, or the 4 other iMacs that have had the same thing happen to over the past couple of years. As a Certified Tech, I'm still baffled by it and can't explain it, but I've "fixed" 4 iMacs (including my own) that this has happened to.
  14. as11ley macrumors 6502


    Aug 19, 2013
    United Kingdom
  15. Philip S, Jan 20, 2015
    Last edited: Jan 20, 2015

    Philip S thread starter macrumors newbie

    Mar 21, 2014
    Thanks for the response!

    Hi guys,

    Wow! I'm overwhelmed by the amount of positive feedback. I honestly thought this thread would quickly be buried under others.

    Let me try to answer some of your questions and maybe provide some clues about what went wrong.

    To Westom:

    Thank you for your comment. Nobody actually told me I'd experienced a surge. I meant that a google search led to several pages claiming that macs were vulnerable to both surges and blackouts.

    In my case it was most definitely a blackout, but I'm not sure what caused it. I can only assume, since it was the last appliance switched on before the blackout (ie; we lost all power immediately when I powered it up), that there were too many appliances running and the computer was the straw that broke the camels back?

    There was no discernible odour of burning, no.

    Unless it was such a tiny amount that I didn't notice it. I haven't opened the Mac up yet (since I haven't ordered any replacement parts yet), but if I do it might reveal some evidence of burning somewhere. Worth a try? (quite a lot of Torx screws to go through to look at the inner workings if it turns out a visual diagnosis is a waste of time...)

    I'm interested in those meters you mentioned. Can you give a bit more info about what they are called and if it's possible to buy them online? I live in Japan but I'd prefer one with English instructions, so I'd rather import one.

    About the breaker, I've no idea if Japanese breakers look completely different from American ones (I grew up in Ireland), but this is the one in my apartment:

    To BlueFox:
    Yes, right after I realised it was refusing to start up I tried unplugging all the Mac's peripherals and power cable both for a few seconds and for several hours. Still no signs of life... :(

    To dazzer21:

    Yes, I had also considered the possibility that the fuse was blown, however the power cable is made in a way that is not easily accessible (as is the norm for Apple hardware items).

    I would assume the fuse is inside the plug that goes in the wall socket, but both ends of the power cable have similar details printed on them. I'd prefer to be 100% sure where the fuse is located before dismantling the wrong end of the power cable to check. :)

    Here is all of the text printed on each end of the power cable (Japanese two-pin outlet]:

    Plug (into back of Mac):
    7A 125V~
    Volex APC13G

    Plug (into wall):
    [above the pins] Volex, [then a diamond containing these three letters]PSE, VOLEX J
    [beside each pin] G [&] HG
    [below the pins] M755, 7A, 125V

    This is a photo of the power cable (both ends)
    To as11ley:

    I tried a PRAM reset - no dice - but I'm not sure about SMC reset. How do you do that? (It's possible I already tried it)

    Thanks again to everyone. The MacRumors forum community is so friendly and eager to lend a hand, it truly is a godsend. Thank you! :)

  16. Philip S, Feb 6, 2015
    Last edited: Feb 7, 2015

    Philip S thread starter macrumors newbie

    Mar 21, 2014

    I was fully expecting that none of the diagnostic LEDs would be lit, however, the first one lights up when I plug it into the mains,
    I know that no LEDs indicates the power supply, unit isn't receiving AC, and LED 1&2 on means power is available and system is on. In my case, only the first LED is lit. Clearly the power supply unit is receiving AC, but the logic board is only detecting trickle voltage.

    Also, I should mention that the LED flickers slightly. It doesn't blink on and off, but flickers slightly.

    It seems to me that a faulty power supply unit is the most probable cause of the problem. What do you guys think?
  17. NigelHow macrumors newbie

    Feb 24, 2015
    iMAc and power cut off

    I switched off the power to my house and now my wife's iMac (purchased Nov 2011) will not restart. It's dead, no fan, no disc noise, no image. Last time I did this I had to take the iMac to the local Apple store and it powered up first time, and with my power lead. I had packed the iMac the previous evening so there was no power cord connection for 12 hours.
    I know, call me 'stupid', I've done it again. This time I have unplugged the power cord for 10 minutes and tried again, no joy.
    I do not believe this has anything to do with power surges, surge protection, etc. I do believe that there is some type of protection functionality within the iMac that I am not able to get past.

    Any ideas please.
  18. Fishrrman macrumors G5


    Feb 20, 2009
    Nigel wrote:
    [[ This time I have unplugged the power cord for 10 minutes and tried again, no joy. ]]

    This suggestion may be of no use, but...
    - try leaving it unplugged all night
    - also, if the RAM is removable, remove it and then re-install it the next morning before you attempt the restart.
  19. NigelHow macrumors newbie

    Feb 24, 2015
    Problem fixed.
    I did leave the power cord out for 12+ hours yesterday and the iMac is now up and running. This is in effect the same solution that the Genius guys 'got lucky' with a few months ago.
    Time for Apple to 'fess up': there's either a bug in the system or a safety feature which needs explaining (how many hours unplugged is required) and probably modifying.
  20. dyt1983, Feb 25, 2015
    Last edited: Jun 1, 2015

    dyt1983 macrumors 65816

    May 6, 2014
    edit: To remove personally identifying information not relevant to the thread.
  21. MCSN macrumors regular


    Feb 7, 2012
    consider yourself blessed by the apple genius's that employed such features so that your computer may once again live.

    buy a surge protector, its a small investment for the life of the machine. power failures happen all the time, and having a way to protect the machine from fluctuations or power failures is worthwhile and you can find them fairly cheap. you can also see if there are any in thrift stores or in community free boxes if $$ is an issue.
  22. westom macrumors regular

    Nov 8, 2009
    Unfortunately these urban myths are taught (by advertising) to naive consumers. First indication of a myth is missing numbers. For example, how does a power fluctuation or failure (near zero or zero volts) create a surge (thousands of volts)? Obviously, it doesn't.

    An informed consumer can read that number on its box. Its 330 let-through voltage means that protector ignores everything until 120 VAC well exceeds 330 volts. That does not happen during blackouts.

    Advertising promotes a protector or UPS to protect from all anomalies. A UPS provides temporary and 'dirty' power during a blackout. A surge protector does nothing for this anomaly - as manufacturer specification numbers also make obvious. Different solutions apply to different anomalies.
  23. MCSN macrumors regular


    Feb 7, 2012
    not really sure what you are suggesting as an alternative. but I have not lost a single appliance with a surge protector. and as far as dirty energy is concerned, its something that is used all the time with solar/wind hybrid setups and with multiple grounds and lightening protection, its common to use surge protectors for one of many safety switches. having a switch to automatically disconnect equipment upon a power failure is fairly routine. i certainly wouldn't care to take mine off. perhaps in your grid safe world you can arm chair science. but when the power goes out at my house, the equipment is off. and that's all that's expected.
  24. westom macrumors regular

    Nov 8, 2009
    If protectors are effective, then listed are many appliances, without protectors, that were damaged. How many clocks, dishwashers, cable boxes, dimmer switches, furnace controllers, CFL bulbs, radios, ovens, and recharging mobile phones did you replace? Since potentially destructive surges occur maybe once every seven years - another relevant number.

    Does not matter what did not fail. Using your reasoning, most appliances without protectors must be damaged. Otherwise, junk science reasoning exists. Which ones failed?

    Long before recommending a solution, first the anomaly is defined. Which anomaly exists?

    OP describes an unknown anomaly that tripped a circuit breaker. And a resulting blackout. His solution begins by identifying what tripped that breaker. Including identity of the breaker type.

    What does a protector do? It does not avert a blackout. It does not avert a tripping breaker. Its failure (due to undersizing) might even create a blackout or tripped breaker. So a protector was recommended to solve an anomaly that does not exist? How does that protector avert the OP's blackout? Which anomaly were you trying to avert?

    Due to advertising, most recommend a protector to magically protect from all anomalies. Protector does nothing for the OP's symptoms. Only advertising says a protector will cure all ills.

    Unlike you, I did this stuff for decades. So I am posting numbers and you are using junk science reasoning. Please keep your snide insults to yourself. Seven question in this post can be answered IF you knew this stuff. Please include numbers to justify your reasoning - without any more cheapshots.
  25. MCSN, Mar 3, 2015
    Last edited: Mar 3, 2015

    MCSN macrumors regular


    Feb 7, 2012
    Well I would avert making a cheap shot, because Apple has already done the math, and provided during power outages, a way for the unit to either restart after power failure, or to shut down for a period of time before becoming able to restart. which is no different than a fuse that trips and resets.

    and light bulbs are susceptible to freak power incidents. in the city you have less frequency with power surges because you have far greater lightening defenses and capacity.

    in our rural example which can be compared to others in other countries, who have limitations imposed on their grids, because of lack of structural development or maintenance, or by rural factors - power surges can occur due to weather. untimely, freak, outside the box, over the equation, unexplainable, most often times unprovable incidents where things do go out. and appliances that do not recover.

    i've seen lightening crawl like a spider over our hillside, and yes, the power did fluctuate, it did go out. lights burst, as well as transformers. and thankfully because I have switches and protection, my equipment was disconnected automatically without having to lift a finger, because I invested in surge protection, and further in switches, fuses and shut offs.

    i'm not saying that you are not correct in the evisceration of true science from advertising when it comes to surge protection marketing. but there are still cases in the world, where freak anomalies have not been eradicated. i admit, that while you are grid based and within a blanket of modern age safety, a power surge protector may not be the end all and may be less useful. its one switch among many to employ and may not protect your devices.

    one is that many of the so called power strips employ methods to reduce power usage, when an appliance is in a standby mode. when the item is not in use, it can power it down. whatever it is that it is there for, and whether or not it functions in that manner according to manufacturer specifications, is at the least tested by consumers. and with reviews you can weed out the unsavory and find models that can provide at least one level of protection or not.

    for mine, I have units plugged in, and some are on all the time, and some are on a switch that if the power goes out, those plugs stay off. If I leave the home and I want them off, I press the remote control button and they switch off. If I am not home and they are left on, and my power goes under 11v, everything is switched off automatically. It is a protection in the power inverter, in the solar wind controller, there's a layer of protection inside at the power strip.

    I do not have to worry about fluctuations of power, and I have a power meter that tells me when my voltage goes under 12v. Whether or not you see it. Is that the case for the poster? probably not. However, these issues are raised for people who have these issues as they present, when seeking advice in forums.

    There's nothing here that would convince anyone that a surge protector is good or bad. If you do not like surge protectors and recommend people not having them, your comments are here for consideration.

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