Buzzing noise, turns louder when brightness is up

Question

iMac Intel 21.5" EMC 3068

A1418 / EMC 3068 / iMac 18,1 / 2.3 GHz dual-core i5 processor. Released June 2017.

33 个问题查看全部

Rob Smeets @robsmeets

声誉积分: 11

1

发帖于: 2021年1月18日

更多选项

Buzzing noise, turns louder when brightness is up

Hi all!

A couple of months ago I upgrades my iMac 2017, 21,5” model with a SSD and RAM.

It worked perfect. I was running BigSur. After the BigSur update from 11.0 to 11.1 I’m hearing a buzzing noise. I first I tought it was the fan, but I dont think so. I installed ‘Macs Fan control’ and turn down the speed. The noise didn’t go away/decrease.

When I decrease the screen brightness to almost 0 then the noise is almost gone.

What could it be?

Thanks!

Hi all,

I didn't repair the Mac. All functions were working, noise didn't get louder so I went with it.

After working on the Mac I shut it down and after 45 minutes I want to start working again…The Mac did not start up. Nothing, no noise, connection, screen. Also disconnected power cord.

What to do? Replacement of PSU?

回答此问题我也有这个问题

这是一个好问题吗？

是否

得分 0

2条评论:

Can you determine which area in the machine the buzzing noise is coming from?

由 Zachary Lunte 完成的 2021年1月18日

Bottom left corner I think

由 Rob Smeets 完成的 2021年1月19日

添加一条评论

2个答案

Can you determine which area in the machine the buzzing noise is coming from? — Zachary Lunte

Mark D Schlossman @consistent 声誉积分: 4.7千 19 11 9 · Answer 1 · 2021-01-18T13:17:59-07:00

Mark D Schlossman @consistent

声誉积分: 4.7千

19

11

9

发帖于: 2021年1月18日

更多选项

It sounds like a power supply issue or

这个答案有帮助吗？

是否

得分 0

5条评论:

Logicboard replacement

由 Mark D Schlossman 完成的 2021年1月18日

Yes, it think so. You wrote "Or"....;) ?

由 Rob Smeets 完成的 2021年1月18日

@consistent logicboard? Never heard of that. What is that for?

由 Rob Smeets 完成的 2021年1月18日

Rob logicboard on 2015 15 inch MacBook pro can have that problem. Bottom left is a power supply

由 Mark D Schlossman 完成的 2021年1月19日

Do this How to find and read the Diagnostic LEDs

由 Mark D Schlossman 完成的 2021年1月19日

添加一条评论

Dan @danj 声誉积分: 459.7千 Self employed contract worker 35 305 965 · Answer 2 · 2021-01-18T15:53:43-07:00

Dan @danj

声誉积分: 459.7千

Self employed contract worker

35

305

965

发帖于: 2021年1月18日

更多选项

What you are hearing is a coil hum/whine. Your system has transformers and inductor coils which can become loose in their cases so they vibrate.

It has nothing to do with the macOS release your system has on it.

You’ll need to open the system up and carefully try to narrow down where the sound is coming from so you can isolate out the part that will need either replacement or repair.

这个答案有帮助吗？

是否

得分 0

2条评论:

Okay...but what part controls the brightness of the screen? When I turn up the brightness the noise gets louder.

由 Rob Smeets 完成的 2021年1月19日

There are two parts the power supply as well as the logic board. Opening the system and listening is really the only way to isolate out which.

由 Dan 完成的 2021年1月19日

添加一条评论

iMac Intel 21.5" EMC 3068

Buzzing noise, turns louder when brightness is up

Update (03/04/2021)

2个答案

添加你的答案