⟐ Answer accepted March 31, 2026 at 12:30 MST

Do I have to change the power supply as well?

⟐ Commented February 27, 2026 at 6:04 MST

It is for LCD Flex Backlight Cable

I have noticed that there is a small print on the male part which says: "MXL 3H" (the letters are really tiny)

Ideally, i would love to get this extension cable shown below but the only offer I can find is 160$ with shipping which is too expensive for me.

-------------------------------------

Some context:

I am modifying fully working IMac to an external monitor, but I also don't won't to lose the ability to use it as a real IMac.

So I am extending the two cables coming out from the display (LCD edp and LCD backlight) and two female ports to which these cables would connect, outside the aluminium frame through a hole made in the casing.

On the back of the IMac (where the 4 cables would be coming from the hole) I will place a regular "convert old IMac into an external monitor" board.

With such configuration I can now switch between

1. using the IMac as an regular bought product (the EDP and Backlight cables are connected to the extensions which lead to the dedicated ports on logic board)
2. and
3. it serving as an external display (cables are connected to the external monitor board).
   
   

I can plug and unplug the switches manually, but it's not the best long term solution, because the LCD EDP cable and port can be easily damaged.

Ideally the best way would be to have a switch for both backlight and edp lcd cables but i couldn't find any. Is there anything like this even?

⟐ Commented February 23, 2026 at 22:48 MST

I created a bootable external drive with Ventura. The external drive will not mount. It was erased and reformatted with GUID table; and APFS file type. I have completely lost the 3T fusion drive and 128 GB SSD.

Help!

⟐ Answered February 20, 2026 at 5:23 MST

⟐ Answered February 15, 2026 at 12:40 MST

⟐ Commented February 01, 2026 at 11:09 MST

Running a new Samsung EVO 870 2TB SSD on the iMac 27" mid 2017 with a OWC in-Line Digital Thermal Sensor HDD Upgrade Cable and OWC NWTADPTADRV NewerTech AdaptaDrive. Running Monterey 12.6.

Opened it all up, all went well but now the fan speed has been set at max and doesn't slow or stop at all.

Have tried majority of third party software that claims to allow fan speed control in these situations. Macs Fan Control, HDD Fan Control, as well as about 3 other popular ones.

• Safe mode doesn't stop the fan.
• Diagnostic gives me PPF003 and PPF004 codes suggesting an error on the fan. Obviously!
• Fan still runs in recovery mode.
• Have reinstalled the old Macintosh HDD without the thermal sensor cable adapter (back to original) but the fan still runs like crazy.

Wondering if it's something I've done. Is it the logic board now playing up or is it OS based not allowing me to run a drive upgrade?

Could it be a fan error (even though it's running at full speed) and a simple replacement would work?

Thanks in advance for all your guidance.

⟐ Answered January 17, 2026 at 7:47 MST

First, bravo for this particularly well-done guide.

I recovered the hard drive of my 2016 Intel iMac, which is 10 years old and definitely down (except for the hard drive of course), so that I could read it again (not copy it) on a new iMac 24 Mac.

What I would like to do is retrieve certain files and be able to read them again or save them on the new Mac.

On the one hand, is there a compatible software to install on the new Mac that would allow this proofreading,

And on the other hand, how to connect the old disk to the new computer: by a 'box'? And with which cable?

If you could answer my question, it would be a great service to me, and I thank you very much in advance.

Sincerely,

Rold

⟐ Answer edited January 07, 2026 at 17:53 MST

I used to use SM951 AHCI in Mac Pro 5.1, 6.1, all Retina and Air 2013-2015 but what about NVMe once? Have anyone tried?

⟐ Commented November 28, 2025 at 13:00 MST

Can it be replaced with older (2014/2015) models displays?

⟐ Answer accepted November 17, 2025 at 20:08 MST

I’m in the process of upgrading the Fusion Drive and the CPU of my 2017 27” iMac. I have already maxed the memory with 64gb Crucial 2400 MHz DDR4 RAM.

I have been reading around, regarding upgrading to M.2 NVMe, and its all quite confusing and often contradicting which SSD use and which adapter to get.

Below are my current components, and what I wish to get my nerdy hands on:

CPU:

• Bought 4.2 GHz intel core i7-7700k (to replace my 3.4 GHz i5 CPU)
• Bought Grizzy thermal compound paste

SSD:

I currently have the 1TB Fusion Drive, and to be honest, It just isn’t fast or reliable. Thus, I want to:

• Remove the HDD part of the Fusion and replace it with my existing Samsung 860 EVO 500 GB SATA 2.5" Internal SSD (I will use it as external storage drive, but located within the iMac)
• Replace the SSD part of the Fusion with a faster NVME M.2 SSD, but I am not sure which of the following to get:
  • Samsung 970 EVO Plus 2 TB NVMe M.2 (is it still the case that I need to update the SSD software, using a windows PC, before it is compatible with MacOS?)
  • Samsung 970 PRO 1 TB NVMe M.2
  • Sabrent 2TB Rocket Nvme PCIe 4.0 M.2 2280 Internal SSD
  • Samsung 970 EVO 2 TB NVMe M.2
• Queries:
  • HOWEVER, I am not sure which is the ideal to use, and I’m undecided which is the best compatibility for my 2017 iMac…
  • I know the Sabrent is PCIe 4.0, which is overkill, but its 2TB is cheaper than the 1TB or 2TB PCIe 3.0 Samsung (970 EVO, 970 EVO Plus, 970 Pro)
  • Is there still the issues with hibernation crashing, when using NVME M.2 ssd in Macs?

SSD Adapter:

• To make the NVME m.2 SSD work, I will be needing a M.2 nVME SSD Adapter, and I have the following two (from Sintech) in mind:
  • Sintech NGFF M.2 nVME SSD Adapter Card (small adapter)
  • Sintech NGFF M.2 nVME SSD Adapter Card (longer adapter ‘card’)
• Queries:
  • Which of the two are best, given the SSD’s Im considering?

I hope to get some feedback, so I can make the right decisions from the get-go.

I will update this thread:

• During the upgrade phase
• Post-upgrade,
• Before-after performance

Hope to hear back soon!

regards,

Frederik

Disassembling and the installation process is not for the faint hearted - it takes a long time, and just a simple small error can prevent the iMac from powering on at all - after installing the CPU, the iMac didn’t power on, so I had to disassemble everything again, and after retracing my steps, I hadn’t properly seated the new CPU (it is not easy to hold the heat sink in place and screw in the bracket on the backside of the motherboard).

however, after reseating the CPU properly, the iMac powered on, and I checked everything was working before I applied the adhesive strips from Ifixit.

The following has successfully been installed in my 2017 27” iMac:

• i7-7700K (4.2Ghz) CPU
• 2TB Samsung 970 EVO Plus NVMe M.2 (I had to update the firmware with a bootable USB drive before the macOS could detect the drive)
• 500GB Samsung 860n EVO SATA 2.5”.

So, how is the performance? it is faster, MUCH faster, in everything from boot-up to document browsing and photo editing in various Adobe C programmes.

In gee bench 5, this Mac has a similar single-score performance to Intel’s I9-9960X (this is a 16 core processor costing $1600+) and a multi score has a better multi score than Intel’s i7-9850H (this is a 6 core processor costing $450+) - however, most surprisingly, this upgraded Mac performs better than the i7-7700K Apple shipped in their 2017 iMacs.

Here are some results:

It has been an exciting (and nerve-wrecking) experience to upgrade this iMac, and if you have any queries or wanting tips, just ask on this thread!

Frederik over-and-out :-)

⟐ Commented November 16, 2025 at 5:53 MST

⟐ Answer edited November 15, 2025 at 5:21 MST

⟐ Answer edited September 17, 2025 at 8:59 MST

⟐ Commented August 21, 2025 at 3:53 MST

iFixit does offer a blade drive replacement kit ,but in the directions for tackling this install it indicates that this blade drive is meant to be used in conjunction with an onboard hard drive or SSD. Will the blade drive in the kit operate as a stand-alone drive, or is it only intended to be used in conjunction with a fusion hard drive?

If I buy the blade drive in the iFixit repair kit, can I switch the entire operating system over to the blade drive/fusion drive configuration—or is there no means of connecting any kind of hard drive or SSD to the motherboard in this particular model?

Any suggestions or help would be greatly appreciated as iFixit seems completely unaware of this kind of configuration and can offer no help.

Thank you!

⟐ Answer edited July 23, 2025 at 18:06 MST

Despite, luckily, finding out about needing to cut out the tape for the 2017 iMac mic, I’ve still ended up with it working. It was fine with tape in place prior to sealing, but stopped working after sealing. No sound reported at all.

Attempted remedies:

Having opened it back up, I cannot get it to respond again. I’ve carefully unseated the cable to the ZIF and reseated it in case I’d not got that firmly set. I’ve tried it with the iMac lying down and screen slightly raised to provide a clear route to the mic. I used the sticky side of some insulating tape to dab the mic area in case dust had got in. I wanted to try the current mic off body in case the hole has something deeper in it (and just shoving a cocktail stick in the hole with a mic at the other end seems a bad idea). I have a new mic on the way as the final backup.

Questions

• Does anyone have any other suggestions of things to test before giving up on this mic?
• Could anyone tell me how to unseat the current mic and mount the new one?
• How does the mic work in that position behind the screen?

⟐ Commented July 17, 2025 at 4:23 MST

First part: 970 EVO NVMe with heatsink installed. Recognized @ Link x4 and great speed. SSD installed and MacOS Catalina reinstalled. Very happy so far.

Second part, a day after: Removed CPU, installed i7-7700k. Struggled a bit with heatsink like everyone it seems. But once done I felt confident that everything was done right, so I re-assembled everything. But the power switch didn't trigger anything!

• LED 1 is on as soon as I connect the iMac to the external power cord.
• Power switch cable seems intact and connected to PSU. PSU and logic board cables all disconnected/reconnected with great care and seem intact.
• Tried to short both power switch pin to start up the Mac. Nothing happened.

Does anyone have any suggestions or comments on what the problem may be?

• I've ordered a new PSU for safe measure. I can't find a spare power switch button (the only part available that has it is an entire empty housing!).
• Can't find a spare power supply control cable (between PSU and Logic board) for a 2017 iMac. But there are some for the 2011-2013 iMac which looks the same as for the 2017 version.
  

Tempted to order that. Does anyone know if the 2013 and 2017 use the same power control cable?

After discussing with friends, one plausible explanation could be that my CPU upgrade went bad. Such as static electricity frying the Logic board. Or the CPU is bad. Even though I've been careful all the way. However, if I understand the explanations regarding the logic board LEDs function, it seems that not even having the LED 2 or 3 on would mean my issue isn't yet entirely related to the Logic board or the CPU. Anyone can comment on this?

I would be very grateful for any suggestions (at least it'll boost my morale, as right now if the new PSU doesn't work, I would have probably to sell the iMac for parts!!)

Thanks

Seb

Just received the new PSU (see picture). Installed carefully (making sure I discharge any static electricity from my hands prior). Reconnected all wires, after inspecting them (see picture). And unfortunately I have the same result: the power switch, which seems to be 100% intact (see pictures), doesn’t trigger any response. Fan doesn’t spin. No second LED.

Could it be the main power cable socket (buried under the bottom bezel of the imac housing)??

Any suggestions welcomed!

Disassembled the Mac again. Look very carefully for damaged cables, or sockets… None found! Took a picture of the wires coming from the main power socket (see below). Everything looks fully functional.

Could this be a back Logic Board??

I can finally breath: Removed the new CPU, installed the old CPU and I’ve got the board to boot up. Did not perform a full reboot with the LCD on. I will make another attempt at upgrading tomorrow with another CPU, so I had only the PSU and Logic board mounted.

Is this a Bad CPU or it wasn’t mounted right, I can’t say for sure. But the Fan started to spin at max speed without stopping, so that got me thinking and decided to go for the i7-7700 instead of the 7700k!

Now, I got to improve my tension spring loading technique. I concur with others that the tension produced by this spring is excessive (Judging from the residue of thermal paste which had been completely squeezed out to the sides when I removed the CPU). So I’ve kept a more important gap between the mounting spring and the logic board, than what I had originally measured (<1mm). See pictures.

Hopefully my next post will be about completing this job… Wish me luck.

Final update: Finally got the system to work.

How: The short answer is you have to unbend the metal spring underneath the CPU!

There is way too much tension in this spring, this put so much strain on the CPU that it bends it. Some pins are then no longer connected. When the LED 1 or 1-2 lit up and nothing more it just means that.

I’ve tried a i7-7700k twice, reinstalled the i5-7600, then tried and kept a i7-7700 finally. So I’ve got plenty of trials to figure all this out.

I will now answer questions :)

⟐ Commented July 15, 2025 at 10:24 MST

I recently bought an iMac 27" 5K (2017) as-is with power issues, and I’ve already opened it up for inspection (It has never been opened up before). I’m hoping to get advice from anyone experienced with this model before I spend money on parts.

When I press the power button:

• LED 1 turns on (AC power detected).
• LED 2 turns on after that (logic board gets power).
• LED 3 flashes very briefly (for about half a second), and I hear a faint click sound from inside.

Then it shuts down back to just LED 1 on, no screen activity.

I also recorded a short video showing the LED sequence, so you can see exactly what’s happening.

This pattern repeats every time I try to power it up. No burning smell or visible damage when I opened it.

Would love to hear from anyone who has seen this before! I’m willing to try deeper tests if you can guide me. Thanks so much in advance! 🙏

⟐ Answered June 06, 2025 at 15:56 MST

⟐ Commented February 21, 2025 at 19:00 MST

I tried plugging in a usb mic as well as apple headphones with a mic and it does not pick up voices then either.

Suggestions for repair. I am running latest operating system. Followed numerous suggestions about adjusting settings and nothing works.

⟐ Answered February 14, 2025 at 14:56 MST