Oh gosh. Please keep us posted I really want to know what you find out. Thats really weird.
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(update5/31)This 4th Imac/ hard drive crashed
- Thread starter Zmmin3
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Oh gosh. Please keep us posted I really want to know what you find out. Thats really weird.
I think the iMac has a higher draw and therefore why are you experiencing these problems. There is no way this is the iMac after the 4th one. Can't explain the 2nd iMac, more resilient maybe ? Anyway. You must look at the possibility that the problem may be the wiring in your home.
Well if its because the computer draw so much power, tell me why when I actually turn the computer ON the problem stops????
The problem only occurs when the computer is off or in sleep mode.
When its actually on and I am doing something with it, there is no flickering at all.
The minute it goes into sleep mode or is turned off, the constant flickering comes back.
I could understand it if the the power thing if the lights flickering when I have it on but it doesnt. The problem is only there when its in sleep mode or off.
I know you are all trying to offer solutions and its appreciated....just weird that if the problem is that it draws so much power, the problem goes away when its actually turned on.
I apologize, I missed that earlier in the thread. I thought it only had problems when it was on or attempted to be on. To me, this seems to signal even more that it's your wiring. Just me.
Buy a UPS
Sounds like wiring problem at your home.
well I received my 3rd one yesterday over nighted....
I plug it in...and....it has the same problem as the first one!
Just simply plugging it into the light socket causes the lights in the house to blink. I didnt even turn it on, just plugged it in. Its just like my first refurb which was diagnosed as a bad power supply!
I know this isnt the norm because the 2nd exchange didnt do it.
Now I dont know what to do. I really wanted an Imac and the refurb is what I could afford but seeing as I keep getting all the crap ones and I am tired of the exchange process, I am tempted to walk away from it all now.
So for those keeping score...first refurb basically DOA,
second refurb no problems with the power supply, didnt make the house light blinks,
this third one display is better but back to having a bad power supply.
Sounds like wiring problem at your home.
it the odd order harmonics from the psu ie 7 and 9
they can be greater when the psu is lightly loaded
I will give an example
an office wing at work ( bank ) when i did that silly thing, a three phase supply had 30 amp phase one 30 amp phase two and 30 amps phase three so by maths the current in the neutral should have been zero ,not so on test it was 90 amps and warm to the touch
thats why I do think that you have a problem with you house supply being to light to absorb these harmonics
to answer your UPS question you would need a 750 VA apc , note they are rated in volt amps not watts , in a single phase ac circuit watts = volt * amps * power factor
eg say 200 volts * 3.75 amp at untiy PF would indeed be 750 watts , but in the real world the pf could be as low as 0.6 lag
therefore 200 * 3.75 * 0.6 = 450 watts
which is about enough for a IMac , a 1000va model would be better
they can be greater when the psu is lightly loaded
I will give an example
an office wing at work ( bank ) when i did that silly thing, a three phase supply had 30 amp phase one 30 amp phase two and 30 amps phase three so by maths the current in the neutral should have been zero ,not so on test it was 90 amps and warm to the touch
thats why I do think that you have a problem with you house supply being to light to absorb these harmonics
to answer your UPS question you would need a 750 VA apc , note they are rated in volt amps not watts , in a single phase ac circuit watts = volt * amps * power factor
eg say 200 volts * 3.75 amp at untiy PF would indeed be 750 watts , but in the real world the pf could be as low as 0.6 lag
therefore 200 * 3.75 * 0.6 = 450 watts
which is about enough for a IMac , a 1000va model would be better
It has to be something in your wiring....the odds of having four machines in a row be bad like that are astonomical enough that if they were all bad, you should get yourself a lottery ticket. Then you can win enough to buy a new machine! Don't plug in another one until you have a decent UPS. Or have them plug it in at the Apple store in front of you so you can see that it works.
BTW, I bought a refurb and except for the brown box, there's no way you could have told it wasn't new.
BTW, I bought a refurb and except for the brown box, there's no way you could have told it wasn't new.
Take the computer to a neighbors house and see what happens. I have to agree with the rest of the posts, there is no possible way you have gotten 4 faulty machines in a row. Hope you get it sorted out.
Ask them to plug it in at the Apple Store
Check if the same happens there. No need for overnight test to do this, just plug it in when you bring it in. Just a suggestion.
I got an iMac 24 (2.8) refurb almost a month ago and it is great. Unless absolutely necessary, I am thinking about only getting refurbs from now on. (Have bought 3 other new macs)
Check if the same happens there. No need for overnight test to do this, just plug it in when you bring it in. Just a suggestion.
I got an iMac 24 (2.8) refurb almost a month ago and it is great. Unless absolutely necessary, I am thinking about only getting refurbs from now on. (Have bought 3 other new macs)
Ive only bought 1 new Mac, my first one about 3yrs ago, a mini. Since then I have bought 5 refurbs. Will likely never buy new again as the value of the refurb far outweighs the slight performance gain of new hardware. I bought the same 24" about 2 days after the release of the new iMacs.
Only had 1 issues with a refurb. A Macbook last year was having kernel panics right out of the box. Apple overnighted another unit to replace that one. So I would never hesitate to buy and recommend refurbished from Apple.
Sorry folks for the delay in the updates. I have been on the go constantly since Friday.Apple store called me on Friday afternoon. As far as all the diagnostic tests, they said they tested each component. They all came up as showing as working in normal parameters. Nothing out of the ordinary.
He also mentioned maybe the wiring in the house.
I countered with "If that was the case, why didnt the 2nd one do that then? His answer was that he didnt know why.
I said I could undestand that if it did it under full power but why when its only off or in sleep?
So I went and picked it up Friday night and brought it home. I have not even plugged it in since I brought it home trying to decide what to do with it.
Saturday I climbed up into the attic(all the nasty insulation and dust) to see what it would take to run a new grounded wire to that room and its going to be a major project.
Also been trying to find a deal on a UPS, all the 750vac units are $100. I wonder if I could get by with a 550vac which is about half the price. Then again I dont know if that would solve the problem.
Again though I am still pondering why I had no electrical issues with the 2nd one
So currently its sitting in the box it came in over in the corner.
I really wanted this Imac but if I am going to have to spend extra money and work just to be able run it...I dont know......
Thank you to everyone that has posted and given suggestions
Also want to mention everyone I dealt with at Apple was extremely polite even though at a couple times I was told contradicting things from different reps.
Faulty Electrical Outlet?
Like most folks, I'm inclined to think that this is a wiring issue. However, it could be as simple as the actual outlet you are plugging the computer in to. If the electrical outlet itself has a medium-resistance short, you would see exactly the symptoms you describe. Simplying putting in a plug could cause a faulty electrical outlet to have a high resistance short circuit. When your computer is under load, the electrons prefer to go through the computer loop. When the computer is off, there is pathway through the outlet.
Before you re-wire the room, try simply replacing the outlet in the wall with a new one. And when you have the electrical box apart, make sure that both hot and common wires are not touching each other and that the electrical insulation around each is intact.
When you plugged in your 2nd machine, it could have seated differently or somehow affected the internal short in your electical outlet. This is a quick and cheap step that could fix your problem, especially since Apple seems to think your hardware is okay.
Like most folks, I'm inclined to think that this is a wiring issue. However, it could be as simple as the actual outlet you are plugging the computer in to. If the electrical outlet itself has a medium-resistance short, you would see exactly the symptoms you describe. Simplying putting in a plug could cause a faulty electrical outlet to have a high resistance short circuit. When your computer is under load, the electrons prefer to go through the computer loop. When the computer is off, there is pathway through the outlet.
Before you re-wire the room, try simply replacing the outlet in the wall with a new one. And when you have the electrical box apart, make sure that both hot and common wires are not touching each other and that the electrical insulation around each is intact.
When you plugged in your 2nd machine, it could have seated differently or somehow affected the internal short in your electical outlet. This is a quick and cheap step that could fix your problem, especially since Apple seems to think your hardware is okay.
From page 2 about my 3rd one:
Didnt matter what outlet in the house I used or on what circuit, all had same result. I tried with and without surge proctector, no difference.
Also other computers I have and large TV's do not cause this problem.
So why does the Imac? puzzling
Try it at a friends house.. I can almost bet you it is your wiring ..
The iMac is great, do what ever u can to keep it.
The iMac is great, do what ever u can to keep it.
Zmmin3
As I am an elect engineer with a degree to my name. I ask you for your own safety get a qualified Sparks to test out your wiring asap
not sure as to your location in the world , it may mean a registered , coded sparks , but get a proper one to do the test not a three week wonder as we call them
ask them to pay attention to the earthing ( your name grounding ) and leave you a report as to the status of the wiring , for your own peace of mind
If you rent get the landlord to do it ( they should anyway as part of the landlord code , same goes for gas installations )
just read your post above that makes your wiring 49 years old !!!!
As I am an elect engineer with a degree to my name. I ask you for your own safety get a qualified Sparks to test out your wiring asap
not sure as to your location in the world , it may mean a registered , coded sparks , but get a proper one to do the test not a three week wonder as we call them
ask them to pay attention to the earthing ( your name grounding ) and leave you a report as to the status of the wiring , for your own peace of mind
If you rent get the landlord to do it ( they should anyway as part of the landlord code , same goes for gas installations )
just read your post above that makes your wiring 49 years old !!!!
By all means...plug it in somewhere else (not your house) first to verify it works!
Go to the hardware store and buy one of those plug in wiring testers...they're about $5...tell you if your polarity is reversed, etc. by the use of some LEDs.
Go to the hardware store and buy one of those plug in wiring testers...they're about $5...tell you if your polarity is reversed, etc. by the use of some LEDs.
I said it, other people have said it, why not take it somewhere else and try it first? Friends house, work, church, somewhere and plug it in?
I realize the 2nd machine didnt cause any problems but I would completely disregard that. Seems you are a bit hung up on that fact and using that as proof that the problem isnt within the house.
I realize the 2nd machine didnt cause any problems but I would completely disregard that. Seems you are a bit hung up on that fact and using that as proof that the problem isnt within the house.