iFixit - Active Questions With Device "Mac Desktop"

iMac Intel 27" EMC 2639: 开机黑屏，不停的当，当，当的响声

Mon, 18 Aug 2025 09:57:56 -0700

2019年更新到新系统后，发现开机问题。

根据网上进行reset pram, smc, 都无法恢复

请教各位

⟐ Answered 八月 18, 2025 at 9:57 GMT-7

iMac Intel 27" EMC 2639: iMac 27 late2012,螢幕出現白屏無法開機，不知為何原因

Sun, 24 Nov 2024 21:42:27 -0700

原來是smc佔據大量cpu導致系統緩慢，後來卻完全無法開機

iMac Intel 21.5" Retina 4K Display 2019: I hope to see the replacement ssd and ram tutorial

Tue, 24 Sep 2024 20:24:52 -0700

替换ssd和ram，但是没有教程，不敢启动，请给指点，或者给我一些建议，谢谢。

⟐ Answered 九月 24, 2024 at 20:24 GMT-7

iMac Intel 21.5" Retina 4K Display (2015): iMac 顯示屏有一條垂直線

Tue, 16 Oct 2018 08:58:27 -0700

iMac 顯示屏有一條垂直線. 有大大有方法維修嗎？

我只用了一年多

iMac Intel 27" Retina 5k Display: iMac 27" 5k 2015 主機板能升級 iMac 27" 2017 的主機板嗎?

Sun, 16 Sep 2018 19:23:30 -0700

我能將 imac 27" 5k 2015 主機板升級使用 imac 27" 2017 的主機板嗎?

iMac Intel 20": Wifi says it's connected but the internet

Tue, 28 Apr 2026 06:57:08 -0700

The wif says it's connected to the router but the internet doesn't work

⟐ Commented 四月 28, 2026 at 6:57 GMT-7

Mac Mini Unibody: 2011 Mac mini (Radeon 6630M) Way Underperforming?

Tue, 28 Apr 2026 05:04:36 -0700

I picked up one of these Macs cheap on ebay. I was formerly using a 2010 mini with the nVidia 320m integrated GPU for classic retro gaming. The system is connected to a TV and a PS4 controller. I mainly play emulated via OpenEMU, and also bootcamp into windows 10 to play GTA Vice City and GTA San Andreas.

Somehow I completely forgot that Apple ever made a discrete GPU Mac mini. Having realized that, I looked up GPU benchmarks and found that the 6630m GPU is kind of decent. Many times mower powerful than the 320m that came before it, or the Intel HD 4000 that came after it. Based on benchmarking the 6630m vs the minimum GPU system requirements for GTA4, I should be able to play that game on it too!

Those are the specs. Now here's the reality. The mini's GPU runs really good for half a minute or so? Then the fan in the mini maxes out, and the GPU throttles so bad, the framerate tanks. IN FACT, its so bad, that I had to dial back the graphics settings in GTA San Andreas to MATCH what I play on the nVidia 320m!!! So on a Mac with over 3x the GPU performance, I'm effectively getting the exact same amount of real-world performance.

My first thought was, Windows 10 must be broken, I should revert to Windows 7!
But after continued use, I'm not sure that's the issue. The second most obvious problem might be bad thermal paste? I know that replacing thermal paste on Macs is all the rage these days, but its not usually as effective as "reddit" would make it seem. But that said, I am in a case where I'm trying to max this machine out. So maybe its worth while to pop off the heat sink, clean it all down, and put some fresh paste on it? If I do go this route, is it worth buying some fancy kind of paste, or will any new, unopened paste be fine?

Any other thoughts on what might be going on? I would be very happy if I could use this mini to play GTA:SA at full native 1080p, and if I could play GTA4 at any decent, playable graphics level.

⟐ Commented 四月 28, 2026 at 5:04 GMT-7

iMac Intel 27" Retina 5k Display: Is Velcro or 3M Dual Lock a good substitute for display adhesive?

Sun, 26 Apr 2026 19:06:35 -0700

I have an early 2015 iMac with a fusion drive setup where the SSD expired. I plan to replace it with an SSD and use the hard drive from the configuration in an external enclosure. This is an aging system, though, and at some point I plan to convert the iMac into a monitor, so I'd like to be able to access to the internals without buying another set of adhesive strips. I saw a guide on using magnets for this, but it doesn't include any good way to attach the bottom of the screen. I'd like to know if 3M Dual Lock (a stronger Velcro substitute) is a viable alternative to the adhesive, and if so, how much do I need of it to hold the screen on well?

⟐ Commented 四月 26, 2026 at 19:06 GMT-7

iMac Intel: Lots of old parts - what to do with them?

Sat, 25 Apr 2026 05:55:47 -0700

I have several 27" iMacs in various states of disrepair as a result of repeatedly breaking the LCD on mine. What can I do with the parts?

Ideally I'd love to sell them for whatever I can get cause times are hard right? What can I do besides recycle them?

I have parts for 4 complete 27" 2015 iMacs including cases, power supplies, mother boards, speakers, fans, stands, etc....

Most of the electrical components either dont work or I have no way of testing them. I just want to get them off my desk at this point.

⟐ Answered 四月 25, 2026 at 5:55 GMT-7

iMac M1 24": Horizontal lines over iMac 24 screen

Wed, 22 Apr 2026 06:34:42 -0700

Hi,

I got horizontal lines over the display! During the warranty period they replaced the board ( it blacked out ) and now this is happening. They refused to replace the device saying out of warranty and asked to replace it :-|. They were not even sure that changing the display will fix the issue. I am hesitant to replace the screen as I am better off to buy a new one rather keep repairing the faulty product.

Is there any way to fix it?

Tried
- Reinstall the OS
- External Display = Works fine
- Reseating those 3 cables

Lines kind of flickers, may be some lose cables?

Please help

⟐ Commented 四月 22, 2026 at 6:34 GMT-7

iMac Intel 27" Retina 5K Display 2019: Microphone is broken after upgrading ssd

Mon, 20 Apr 2026 15:15:48 -0700

Any idea where i can get that part?

the ribbon is so fragile, looks like it broke

thanks

After changing the microphone for a new one it is still the same problem, no idea what happened, i was being very careful inserting the flex cable on the board.. when removing the original one i pulled it instead of removing the tiny latch because i did not know

Any idea?

Thanks

⟐ Answer accepted 四月 20, 2026 at 15:15 GMT-7

iMac Intel 27" EMC 2639: Slow Write Speed (2TB Crucial Bx500 SSD) No Matter What

Sun, 19 Apr 2026 12:09:17 -0700

Hello,

I have a late 2013 27" that I replaced the failing HDD with a new 2TB Crucial Bx500 SSD.

Write speeds are an abysmal 20-40MB/s no mattter what.

I have also replaced the SATA cable AND enabled Trim.

I have tried also formatting the drive to exFat and then back to APFS with a clean install of Catalina, and then migrated the data again with migration assistant.

Originally, I thought the drive or cable was bad, so I replaced both again.

The issue persists. Write speeds hover from 20-40 MB/s.

Thank you for your consideration and help. I will be sure to respond as promptly as possible.

⟐ Commented 四月 19, 2026 at 12:09 GMT-7

iMac Intel 21.5" EMC 2428: iMac 2011 only #4 diagnostic LED is lit problem after upgrade

Thu, 16 Apr 2026 07:05:48 -0700

Hi everyone, I am kind of new here so here is my little story which I am having at the moment.
I have been diagnosing my iMac 21 mid 2011 for about a month, and I cannot get it to start back up no matter anything that I've tried and diagnosed, I only get #4 diagnostic LED to lit which is for LCD panel/inverter, nothing else.

First I thought it was the PSU on it's way to failure from age, but purchasing a new replacement didn't made any difference.

Then I've thought the internal connector which goes from power supply to the mb (motherboard) which gives it power and it may have been damaged while I disconnected it from the PSU, and I may have to get it, nothing changed.
But, one interesting thing is that both PSU's giving high pitched noise and "clicks" one or 2 per 3 seconds or so. I can record it as a voice memo if needed.
After that I thought the iMac's chassis may shorting components inside, so I measured voltages with the beeper on multi, everything is fine on that side. (no beeps)

As motherboards rarely fail, I also purchased a replacement, which also did no difference.

I think I have verified everything that could come to my mind, and I simply cannot get it power on no matter what I have tried. I am mostly specialist in laptops, so this is my first attempt and experience on getting inside an iMac.
I really hate throwing electronics away, I always try to diagnose them in every possible way. I have no one to ask and who could assist me in helping with this, as everyone who I know are always with their stuff.

If any more info is needed or I may have something missed during diagnostics, please please let me know, I will very much appreciate it.

⟐ Commented 四月 16, 2026 at 7:05 GMT-7

iMac Intel 27" EMC 2429: How to get rid of iCloud lock?

Fri, 10 Apr 2026 20:06:02 -0700

I have a 2011 iMac but It was iCloud locked and when I go to do a clean install it has an EFI lock. How Can I get rid of this?

⟐ Commented 四月 10, 2026 at 20:06 GMT-7

Mac mini (2024): How to repair or replace the power button cable and where to get part?

Wed, 08 Apr 2026 11:16:06 -0700

While upgrading the SSD I was not careful and pulled the power button cable out of the connector such that I now have two bare pins and the plastic connector they go into is torn up. Is the a part number for just the power button cable and where can I order?

⟐ Answer edited 四月 08, 2026 at 11:16 GMT-7

iMac Intel 21.5": Replacing my ssd drive

Sun, 05 Apr 2026 10:21:47 -0700

My drive is dead. How easy is it to replace (or is it worth replacing)? If I do replace it, can I restore my system from a backup of the drive or do I need to install a new operating system on the new drive? It is a 21.5 “ 2.7GHz Intel i5.

iMac: I have no sound in chrome on my iMac

Sat, 04 Apr 2026 05:38:11 -0700

I currently have no sound in Chrome on my IMAc at startup

⟐ Commented 四月 04, 2026 at 5:38 GMT-7

iMac Intel 24" EMC 2267: iMac dead. used as a monitor lcd panel

Thu, 02 Apr 2026 23:00:39 -0700

Hello , First sorry for my English . I use google translator to help me :(

I have everything you need (or so I think) to use my imac lcd panel (panel LM240WU2 ( SL) ( B4 ) ) as a monitor for other pc

http://i62.tinypic.com/112e876.jpg

http://i61.tinypic.com/2mwxct2.jpg

also I connect the cable from the inverter to the lcd

this http://i59.tinypic.com/f10dts.jpg to http://i57.tinypic.com/f2itxd.jpg

Connect the power cord from the iMac ( white ) energy to the panel. and I connect the power adapter to the board vga 12V 2A

but does not work , connect via a PC to give vga video signal and does not work

do I wrong ?

Help please :(

⟐ Answered 四月 02, 2026 at 23:00 GMT-7

iMac 27" 2017: Will an HDD from an existing fusion drive work with a different ssd?

Tue, 31 Mar 2026 12:30:29 -0700

I have an iMac 2017 that is dead, will not power on, and I would assume it's the logic board since power supply replacement didn't help. I have another one of the same iMac that is working, and I want to move the HDD from the bad imac into the the good one. I want to avoid removing the logic board on the new one if possible, so the question is: can I just move the HDD from the bad iMac to the good one without moving over the SSD from the fusion drive? All help is appreciated, thanks!

⟐ Answer accepted 三月 31, 2026 at 12:30 GMT-7

iMac Intel 27" EMC 2546: Help identify the pinout of the PSU (A1419, EMC 2546)?

Thu, 26 Mar 2026 17:18:53 -0700

Hi all, I am trying to do a monitor conversion and hoping to reuse the PSU. The model number is ADP-300AF T. It has 3 connectors, other than the AC input.

One big 12 pin molex connector connected to the logic board.
One small 2 pin connector connected to the power button.
One small 7 pin connector, connected to the logic board via a flat cable.

The big 12 pin molex connector is apparently the 12V rail. It's also confirmed by the schematic.

The 2 pin connector for power button is probably a passthrough to the logic button. The PSU usually needs a PS_ON pin to be pulled to the ground to keep on, if it's like an ATX PSU.

The 7 pin connector probably has that PS_ON pin, along with some other pins. I'm trying to figure out their functions. According to the schematic, they are:

PWR_BTN_R
GND
SMC_ACDC_ID_R
TSNS_ACDC_N
TSNS_ACDC_P
GND
BURSTMODE_EN_R_L

So, it confirms my suspicion about the power button. Pin 1 must be the power button pass-through. I looked up burst mode, which I probably don't need to worry about. But I'm unclear about the rest 3:

SMC_ACDC_ID_R
TSNS_ACDC (Positive and Negative)

Can someone shed some light on them?

P.S. does anyone know what kind of connector it is? I hate cutting the original cable. Worst case, I can solder wires to the PCB but it's kinda hard to do with the connector in place.

Schematic:

Connector:

⟐ Commented 三月 26, 2026 at 17:18 GMT-7