Is my power supply dead? (Mid 2010 EMC 2389)

Discussion in 'iMac' started by got556, Jul 12, 2013.

  1. got556 macrumors 6502

    got556

    Joined:
    Jul 7, 2013
    Location:
    Indiana
    #1
    To preface it's been a great day and a horrible day. Got my 15" non retina MBP i7 in today. w00t w00t. Now onto the bad. Apparently I overloaded the electrical in the "office" room and blew a fuse. So I go to reset the breaker and come back into the room to fire up the iMac (Mid 2010 EMC 2389). Won't power on. Hmm...start trouble shooting.

    Reset SMC, PRAM, leave unplugged for copious amounts of time, plug back in, nothing. No sound, no beeps, nothing. Tried using your run of the mill (known to be a good one) PSU cord and still nothing. Removed the two 4GB Cruicial sticks and left the stock 4GB of RAM in, nothing.

    The one thing I haven't done is check the diagnostic LED's. I'm thinking I don't need to at this point.

    I don't mind being hands on, so I'm going to probably be buying a PSU from iFixit and taking the gamble hoping that's the issue. I'm guessing when I went to reset the breaker, a power surge happened and fried it. It was plugged into a surge protector but I see that didn't help any. What do you guys think?
     
  2. Bear macrumors G3

    Joined:
    Jul 23, 2002
    Location:
    Sol III - Terra
    #2
    Surge Protectors can go bad once they handle a large surge. They usually have an indicator when light that shows the status of surge protection

    Did you try plugging your iMac in to a different outlet?
     
  3. got556, Jul 12, 2013
    Last edited: Jul 12, 2013

    got556 thread starter macrumors 6502

    got556

    Joined:
    Jul 7, 2013
    Location:
    Indiana
    #3
    Sure did. Tried plugging other things into the surge protector (MBP and iPhone chargers and connected them), works fine. Also tried going straight to the wall outlet in that room and another room with the iMac. No dice. :( Noticed the surge protector warranty said it will cover up to $150K worth of equipment. Think I should maybe try to contact the surge protector manufacturer? I mean it can't hurt right. And if a surge did kill my PSU and thusly kill my iMac for the time being, that's what that device protection is there for, right?

    ETA: I've read a couple threads about the same issues after power outages, and most have had varying results. Even read some where after two days of being off the grid, they were plugged back in and fired right up. So I guess I'll hold off a couple of days before placing that order to iFixit for a PSU. Shame I'm trying to chase the cause, else I would go ahead and swap out the CPU for a better one, and add an SSD. :p At least I have my MBP to play with for the time being, which will be getting a 256gb 840 Pro and 16gb ram upgrade here shortly (whole reason I went non retina).
     
  4. got556 thread starter macrumors 6502

    got556

    Joined:
    Jul 7, 2013
    Location:
    Indiana
    #4
    Selling an Asus laptop tomorrow which was going to go towards an MBA as a bday present to the gf. Now will probably be using some of the cash to get a new power supply. I have left it unplugged for about 4 hours now and will continue to leave it unplugged until I come home from work at 10 pm tomorrow night and see what happens. I also emailed customer support at Philips about their surge protector I was using when this happened but I am not getting my hopes up there. I don't want a new computer from them or anything like that. But at least let them know I don't believe their product did its job. It was only 3 days old.
     
  5. Chippy99 macrumors 6502a

    Joined:
    Apr 28, 2012
    #5
    Sorry to hear of your woes mate. I would certainly pursue Philips, it's worth a try as you say.

    One thing I would try is this: Whilst the iMac is unplugged, press and hold the power button for around 30 seconds and then release it. Then plug you Mac in and try it again. I have seen this trick work in the past.
     
  6. got556 thread starter macrumors 6502

    got556

    Joined:
    Jul 7, 2013
    Location:
    Indiana
    #6
    Thanks for the kind words. I have tried that...more than once. Held it for 5 seconds, tried, nothing, held it for 15, nothing, held it for a whole minute...(I counted to 60) nothing. :mad:

    I just hope it's the PSU and not the Logic Board....guess I would know more if I took the screen off and watched the LED's. I don't have the suction cups though, but thought about using a windshield mount suction cup for a lifeproof case I used to have, which is stupidly strong. However, I need to tackle such a project on a day where I'm not frustrated and pissed off about why I'm need to do such a thing.

    Really really hope it's not the PRAM battery. While cheap to replace, gonna be an oh so fun time to get to it. (Installing RAM is about the most in depth I have been on a Mac, but I suppose if I have built numerous PC's, assembled my fair share of guns, and built a few motors, I can tackle this. But it's the unknown, and with me not really knowing what the cause is, I hate throwing a bunch of money at this chasing ghosts.) May just resort to ponying up the $80 or whatever it is for the Genius' to diagnose.
     
  7. Chippy99 macrumors 6502a

    Joined:
    Apr 28, 2012
    #7
    Or take it to a specialist 3rd party Apple repair shop. I certainly would do that, personally.

    I have built countless PC's and am generally competent at fixing "stuff", but when I went to replace the HD in my Mac Mini with an SSD, and I read all the horror stories about people ripping the headers off the logic board whilst trying to remove fan or IR connectors, and then when I saw how SMALL everything was inside, I thought "no thanks" and got a specialist to do it for me. Cost £50 which I reckoned was good insurance compared to £350 for a new logic board.

    If you find a good local independent, they won't rip you off for parts and will fix it in no time. Better that than just spending money on a PSU and "hoping" that will do it, IMHO.
     
  8. got556 thread starter macrumors 6502

    got556

    Joined:
    Jul 7, 2013
    Location:
    Indiana
    #8
    Well GOOD NEWS!!!!

    This morning I tried something I read last night. With the computer still unplugged, hold the power button down while plugging in the computer. It booted up, however, fans were running at max speed.

    So I downloaded HDD Fan Control, but it wasn't doing anything. I was finally able to reset the PRAM however, properly. Booted up, fan speed was still at max. So I took a chance and shut it down again, reset the SMC, crossed my fingers when I hit the power button after doing so, and it fired back up like nothing ever happened. Fans are now normal, and everything is GTG.

    We will see how long this lasts, but hopefully all is well.

    Thanks for your input Chippy!
     
  9. Chippy99 macrumors 6502a

    Joined:
    Apr 28, 2012
    #9
    Great news mate - I have to be honest, I thought it was probably toast. Not sure I helped much, but delighted you got it going. Hopefully this thread will be of use to someone else one day, because powering on whilst holding the power button in, is a weird fix. But clearly a great one!
     
  10. Dadioh macrumors 65816

    Dadioh

    Joined:
    Feb 3, 2010
    Location:
    Canada Eh?
    #10
    I believe that what is happening is an SMC Bypass. The same thing works on Macbooks. Basically it tells the machine to boot without the SMC preventing boot due to some sensor issue. However this is usually a temporary fix to allow diagnosis to see which sensors are complaining. To have it start working after the bypass suggests that the SMC was tied in a bit of a knot and needed to be untied ;-)
     
  11. Tailman macrumors newbie

    Tailman

    Joined:
    Nov 4, 2016
    #11
    Having the same issues after a power/ electrical storm, iMac has been starting when in the mood ... till it wouldn't. Did everything you did & it did start. Reset the PRAM, SMC. THen shut down .... would not start back up. Left alone for a couple hours, hooked power back up, held power button as I plugged in & she started. Fan blowing higher than I have ever heard it, PRAM, SMC resets. Shut down & she's dead again. I am going to add new DIMM that I have wanted to install, let her set disconnected for the weekend & see if she'll start Sunday or Monday ... then I'll just "SLeep" if it does start. ANy additional advice? ALSO, any links to how I open her to look at the diagnostic LEDs? THANKS!!!
     

Share This Page