⟐ Answer edited August 27, 2026 at 9:12 MST

I'm trying to revive a Late 2017 21.5" iMac (A1418, EMC 2833) that has been black-screening.

Symptoms:

- When booting, I hear the startup chime, see the Apple logo for ~2-3 seconds, then the screen goes black

- Fans continue running normally

- I tried Internet Recovery (Option + Command + R, and regular Command + R)

- The recovery globe loads, I can select WiFi, enter a name, and even see the macOS Utilities window

- Sometimes the recovery utilities work briefly, but the screen blacks out after ~10 seconds

- I also see occasional vertical stripes / glitch lines on the screen for a split second right before it dies

- I tried resetting SMC and NVRAM multiple times — no change

- I also attempted to make a Ventura USB installer using a MacBook Air, but same black screen when booting from USB

Questions:

1. Given the symptoms + brief visual glitches before black screen, is this likely the GPU failing?

2. Is there a way to boot with reduced graphics (safe mode doesn't seem to help) or disable the AMD GPU in firmware?

3. Should I pursue logic board replacement or is this worth repairing economically?

Any guidance is appreciated — I'm comfortable opening the machine up if there's a safe test path.

Specs: iMac A1418 (21.5-inch, 2017), Intel i5, AMD Radeon Pro 555

Thanks!

⟐ Commented August 27, 2026 at 8:06 MST

It gets into the OS itself just fine, like I can see it working on the screen and it looks perfect, I just have no way to interact with the machine. Weird bit it that it's the same when I hop into recovery and internet recovery, keyboard and mouse are working the whole time it downloads internet recovery but when it actually starts to boot it they cut power. I tried resetting everything back to the factory config but the same issue happens.

I have tried cmd+option+P+R on boot to no avail (it does actually reset because in EFI the mac sees and uses the input devices just fine.) I have tried linux too but when it starts the USB boot, as you may guess, it cuts power to the USB ports and fails to boot. I don't have any thunderbolt 2 cables laying around but I am sure I can order some off ebay or something

I know all my bits work because the machine boots with ZERO errors so I don't understand why it would do this and then continue even after I put everything back how it was. Any ideas?

⟐ Commented August 26, 2026 at 5:07 MST

Hello!

I have a big problem with my iMac.

I can´t start the iMac - there is no gong, fan or something else. Always black screen.

These things i have already done:

- SMC reset

- cleaning the fan

- change the power supply

- change the battery on the logic board

Now i dont have any ideas, what i can do.

I don´t hav a garranty for the iMac - it is from 2013.

If anybody have a idea, please let me know!

kindest regards

Klaus

⟐ Answered August 25, 2026 at 11:13 MST

⟐ Answered August 21, 2026 at 13:07 MST

Have checked the power supply, 12.12 volts on three legs. i hear a slight repetitive clicking from the power supply, so it may be bad?

⟐ Answered August 21, 2026 at 13:00 MST

I deconstructed my iMac and made it into a functioning external monitor after it broke.

I want to re use the iSense camera by making it a USB device. I have heard of people soldering the cables onto a USB for use. The issue is, there is 7 wires and I am not sure which wires to attach to the USB as they only have 4 connections. I have attached an image.

Thanks in advance

⟐ Commented August 21, 2026 at 8:48 MST

⟐ Commented August 18, 2026 at 19:01 MST

⟐ Commented August 17, 2026 at 4:48 MST

⟐ Answer edited August 17, 2026 at 2:45 MST

Regardless of the cost, we still need an answer. As one person commented, some of us may have an existing case or 2010 mini. I noted a similar question posted recently as well.

⟐ Answered August 16, 2026 at 23:51 MST

I ended up being successful, however in attempting to loosen the logic board screw to allow room to to seat the hard drive as the instructions indicated, the screw was so tight I stripped the screw. After quite a lot of struggle I seemed to get the drive seated and it is functioning.

Is there a way to loosen the screw for any future issues?

⟐ Answered August 13, 2026 at 0:28 MST

It came with a Core i5 2400s which is a 65W TDP. The Xeon E3-1280 is 69W. So has anyone tried this before would it work?

⟐ Commented August 12, 2026 at 5:54 MST

I replaced the power supply but no luck (ebay working pull). I am considering replacing the power button next.

It is a 27" 3.4 i7 with 32gb ram and 2gb Vram. Nothing happens when the start button is pressed. It stopped working in February. There were a few crashing that seemed to be related to connecting to wifi before it stopped working.

▪︎are start buttons known for going out?

I'm going to pull the drive and put it in a laptop for the time being: Look at crash report.

Case is still open: monitor is attached but only taped close.

Also if this does start can it run off an external monitor without the screen attached?

It might be easier to work on that way.

Thanks for any help.

(The right speaker is unplugged, I just decided not to remove it.)

Edit: I ordered a replacement PSU and got the same result- a buzzing noise with only LED 1 working. I narrowed down the buzzing to near the top-right of the PSU. Turns out, the buzzing only happens when the computer is attempting to turn on (i.e. after I hold the power button for a few seconds). It stops if I hold the power button for a second or two while it's buzzing. When I remove the PSU data cable, the buzzing I had been hearing stops and is replaces by a higher-pitched buzzing sound that isn't affected by power button presses. (LED 1 still works without the cable, as expected.) I tested each wire in the PSU data cable, and they're all working. I'm thoroughly stumped now.

⟐ Answer unaccepted August 10, 2026 at 20:32 MST

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 August 09, 2026 at 19:05 MST

⟐ Commented August 08, 2026 at 3:12 MST

I have a Mid 2011 Mac Mini (2.5Ghz i5 model A1347) which I bought from the refurb store in 2013.

From mid 2013 to late 2016 it served as a media server, running XBMC/Kodi. Towards the end of that time it started to randomly shut down. I then stopped using it and since then it's been sat in a cupboard.

I was going to wipe it and set it up for my daughter, but I can't get it started. When I try to start it, the power light comes on and I can hear something (I think it's the HDD) and then about one second later it switches off.

Any guidance on troubleshooting this would be much appreciated.

Thanks

Barry

⟐ Commented August 03, 2026 at 14:36 MST

So i have late 2013 27 inch iMac. The fan stopped spinning. I installed TG Pro and sure enough it was showing 0rpm.

So i bought a new fan and followed iFixit guide to install it but even the new fan is not working.

What could be the issue here?

I read somewhere that cold solder on fan controller(?) might be the issue. I have attached the image below of the fan connector area. Can anyone help me point out what i could do to fix this without having to go to Apple?

Apple HT shows “there maybe a problem with fan PPF003“

⟐ Commented July 30, 2026 at 23:53 MST