修理を始めるには コミュニティ ストア

モデル番号A1419 / EMC 3070 / Mid 2017 / 3.4, 3.5もしくは3.8 GHz Core i5もしくは4.2 GHz Core i7 Kaby Lakeプロセッサ (ID iMac18,3) / Retina 5Kディスプレイ。システムは類似しているため、修理ガイドについては旧モデルのiMac Intel 27インチ Retina 5Kディスプレイ (Late 2014 & 2015) を参照してください。

294回答 すべてを表示

オプション

iMac powering off AND on randomly

40 days ago my 2017 27” iMac started powering off and on randomly. It would stay on for anywhere from 10 seconds to a few minutes, shut down again, and also randomly power up again. As on old ACSP, I did all the tricks I can think of and then brought it to Apple, who couldn’t replicate the issue of course. So I brought it home again and it worked fine for 40 days, but now it’s doing it again.

What I find interestIng is that often right before it shuts down, I see the shut down dialog (are you sure you want to shut down…) appear. It’s also interesting that it powers on again after a few seconds or minutes. Haven’t yet found another case that mentions these things. Anyone have reason to believe it’s anything other than a bad power supply? BTW also keep this iMac on a UPS with AVR. Any advice is appreciated.

回答がありました！ 回答を表示 同じ問題があります

この質問は役に立ちましたか？

はい いいえ
スコア 0
コメントを追加

2件の回答

フィルタ：
参考になった順 新しい順 古い順
ベストアンサー

オプション

You should not be getting the shut down dialogue with a failing PSU. This leads me to believe that it's a software issue. I've seen this with systems installed on unsupported Macs. What system are you running?

このアンサーは役に立ちましたか？

はい いいえ
スコア 2

4 件のコメント:

Thanks for the response! I’m using Ventura with all current updates, which is indeed supported. The startup thing is confounding too. Have you seen this before? Can’t think of any reason it would start up on its own accord. Could the power button itself be the culprit?

さんによる

Do you get any message when it restarts?

さんによる

Just that “your system has restarted due to an issue” or something to that effect, asking if I want to reopen windows.

さんによる

Seems you were correct about it being a software issue, as a clean OS install seems to have done the trick. Thanks!

さんによる

コメントを追加

オプション

I’m suspecting you have a outlet power issue. Get an outlet tester see what it tells you.

I think you have a bad ground or the hot & neutral wires are reversed.

このアンサーは役に立ちましたか？

はい いいえ
スコア 1

4 件のコメント:

Outlet tester tests fine. Also using UPS with AVR. Happens with or without the UPS. Relatively new home with pretty clean power.

さんによる

@nuages - What does the console tell you? Look at the log file. You might want to flush it as it can get quite big!

I don’t think you’ll see anything as the output at the time-point won’t be saved.

Let’s follow the AC path from the UPS to your system are you using the protected outlet and directly connected? Try replacing the power cord and do a good inspection of the systems socket for arc damage and/or dirt. You may need a new socket.

さんによる

I’m up in the hills, so I’ll have to check console again when I get home in a couple of days. I’ll probably wipe it and do a fresh install as well for testing purposes.

The iMac plugs into the cyberpower CP1000AVRLCD, battery/AVR side. The UPS plugs right into the wall. I’ll inspect the outlet when I get home. I’ll try a new power cord for the iMac as well. Thanks!

さんによる

Back home. To be thorough, I plugged directly into another outlet, which I had checked for wiring faults, used a different kb/mouse, and a different power cord, no peripherals. Same thing happened.

So I went nuclear and reformatted the internal drive & clean installed Ventura -- probably overdue, as this Mac has been upgraded every year since 2017. I'll rebuild manually rather than migrate the data and see how it goes, but so far so good. Maybe it's fixed or perhaps playing coy before it acts up again, but this way I'll know eventually.

Regardless, thanks for your help in troubleshooting!

さんによる

コメントを追加

回答を追加する

Nuages さん、ありがとうございました！
統計データ:

過去 24時間: 0

過去 7 日: 0

過去 30 日: 3

今までの合計 74