0
Score
barbehenn
11
Asked
After power failure, computer will not start up?
After recent power failure, Imac will not stat up. No sound or any indications. Tried unplugging power cord and re-plugging power cord and depressing the on switch for 10 - 15 seconds, no response. Tried powering from another AC power outlet, no response. Appears power supply has failed. I am prepared to replace power supply but could the problem be something else?
Thanks.
Edited by: barbehenn ( ) , machead3 ( )
1
Score
machead3
21.3k
Answered
Accepted Answer
If you had no (or a cheap) surge protector you could have damaged the power supply. Follow the guide to open the unit then check the diagnostic LEDs.
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I have a surge protector, not sure on the quality. I will check the LEDs when I open the unit. I believe you are right, it is most probably a damaged power supply. Appreciate your help.
If you're really lucky it might be a fuse... some of the power supplies do have an overload fuse... but if it was a brownout (voltage drop) the fuse doesn't help. That's why a battery back up uninterrupted power source is better than a plain surge protector.
Thanks, opened case and measured power supply output voltages with VOM. Found zero Vdc on all pins except 1.2 Vdc on pin 5 and 3.41 Vdc on pin 9. Replace power supply and restored to operation. Relatively easy using Ifixit tools and guides. I was a bit baffled on how to get the case open until I read Ifixit guide and watch a video on the WWW. Thanks for your help.
