Not sure if this is the right place to add this comment, but here goes: I bought a late 2015 iMac 27 which had only a 256Gb blade SSD in it, and wanted to upgrade it with additional storage. I'll not include everything here that I did, however I will mention that I discovered that it had the brackets inside for a 3.5" HDD, but no SATA cable. With a new cable and 2.5" SSD drive in an adapter, I now found that I had no screw posts to secure the SSD adapter in the mounting brackets. I searched everywhere online, but couldn't find any to buy. I procured some (brass) logic board mounting posts with the proper thread gauge to fit the SSD adapter which I then filed to an appropriate round shape that would hold the adapter in the mounding brackets. Problem solved.

By the way: I grabbed one post in my drill to spin them while filing them round. Holding one post in the drill, I could screw a second one into it for filing, lastly placing a finished post into the drill to modify the last post. Worked like a charm!

Hi all. The 5k screen on the iMac 27" I bought on eBay was totally trashed when it arrived at my home. I was able to find a new 5k replacement screen for it (also on eBay...) which works perfectly. I should note that the new screen did not arrive with a LCD Temp Sensor on it. I was able to Carefully Remove the sensor from the old screen and attach it to the new one successfully. Follow the advice in previous comments regarding removal and re-attaching and you'll have no problems (and save some money). I've had zero problems with it in the last year, so I think this could be a viable solution to a missing LCD Temp Sensor.

My 27" iMac was damaged in shipping and I had to replace the display. When trying to replace the display, I found that the case was bent on the top, just barely visible. Makes sense as the top right corner of the display was totally smashed... Check your display fit and alignment BEFORE placing the adhesive strips. This way you can work on straightening the frame without worrying about damaging the adhesive strips.

The case is actually soft, in that it is easily bent. Work only when relaxed and not stressed out! I used my body weight and a small piece of wood as a fulcrum to accomplish the (un)bends. If you place it on a totally flat surface you can see where it's touching and where it's high, so you know where to bent it. I had to use some pliers to get the last bit straight. I used multiple (4 - 6) layers of cardboard under the pliers to prevent scratching the aluminium. Go gently, slowly, checking for alignment / flatness many times, rather than doing too much and having to bent it back again.

The display I bought had some pink protective plastic film covering the camera portion of glass on the back of the display. Be sure to remove this before finally seating the display in place! Not doing so would result in improper focusing and a pink tinted picture all the time.

When replacing the I/O board, be careful to gently lift the microphone ribbon cable out of the way. If you forget, you’ll have to remove the I/O board to get at it again…

FINALLY! All back together…. Lost a screw first time ‘round. Couldn’t find it anywhere. Then as I turned over the case when I had it 95% back together, I heard a rattle. OKaaaayy. Took it all apart again, found the culprit, got it together again — without the shake, rattle, and roll when I turned it over. It now has a 128Gb SSD and a 2TB hdd that will become a true Fusion drive in a few hours. Oh yeah, I installed 16Gb of RAM in it as well.

Great guide!

It's a pain in the butt. There are two plastic shields, both with some sort of circuitry on them so you have to be very careful and methodical here. Then there are about 75 VERY tiny screws holding the actual keyboard in place. I changed it because I had a couple of extra bodies laying around, and the body I wanted had a half dozen dead keys. I actually succeeded and the LED lights actually worked afterwards! I was amazed. It took me a good couple of hours to complete. Don't try it unless you have a lot of patience, time, and a magnifying headset of some sort.