iMac 2017 with sleeping sickness!

Question

iMac 2017 with sleeping sickness!

Hi everyone, I have a 2017 iMac 21.5” which has been working great lately. I upgraded to Ventura a couple of weeks ago and that seemed to go well. Earlier this week we had a power outage. When I switch on my iMac now it constantly goes sleep. It will sleep while doing the initial boot before it gets to the login screen. Then when I wake it the login screen appears and I can log in. I then get between about 3 and 20 seconds before it goes back to sleep again.

So far I have reset the PRAM and SMC but neither had any effect. Is there anything else that I can try?

Thanks in advance and happy holidays to all!

Posted on Dec 23, 2022 5:29 AM

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Answer 1

Top-ranking reply

Paul Waterhouse Author

Level 1

9 points

Jan 5, 2023 3:11 AM in response to Paul Waterhouse

Given the age of the iMac and the fact that I'm pretty technically minded I decided to replace the power supply board myself. It was really straightforward to remove the old one check the model number. I searched online and found several used (but tested) boards for sale so I bought one for UKP22 (around US$25). I have just fitted it and my iMac has sprung back into life again, what a relief!

The work took around an hour all up and wasn't particularly difficult (I followed a very helpful guide on iFixit).

I'm really grateful for the help in diagnosing the problem, many thanks to @hcsitas.

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Answer 2

hcsitas

Level 6

13,970 points

Dec 24, 2022 4:59 AM in response to Paul Waterhouse

Looks like a bad power supply - I’d schedule in-store repair ASAP. The estimate’s free but expect it be at least 300 $/£. Then it’s your call.

Retain the Energy Saver settings after they replace/you replace your iMac with new. All the best!

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Answer 3

hcsitas

Level 6

13,970 points

Dec 23, 2022 7:37 AM in response to Paul Waterhouse

Could you post Settings snapshots of:

Displays > Advanced
Energy Saver and
Lock Screen

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Answer 4

Dec 24, 2022 1:43 AM in response to hcsitas

Hi, many thanks for your help. I have attached the screenshots as requested, it was quite a challenge with only a few seconds to work with each time I logged in! 😆

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