Chosen Solution

I have a Late 2014 iMac 27” (A 1419 EMC 2806, 3.5 GHz) which came with the 1TB Fusion drive. Two questions:

  1. After sitting on a desk, connected to an AVR UPS, in a temperature and humidity controlled room, and never opened, we’re seeing a single vertical line down the right 1/3rd of the screen. Pictures attached. What is this likely to be? An easy/cheap fix? I saw another person said it might be cable related? Line does not appear on external Thunderbolt Display. Wasn’t sure if we were talking cable, display, logic board, video card.
  2. The Fusion drive is basically a 24 GB m.2 caching for a 1TB traditional laptop hard drive. What’s the best replacement if I want to put a 2 TB SSD in? Pull the cache m.2, replace that, removing the 1 TB? Or pull the cache m.2 and simply replace the 1 TB with a 2 TB SSD? I heard they upgraded some of the controller components around 2014/2015 so wasn’t sure the best (most cost effective) SSD replacement would be. I’ve done a lot of repair work over the years, strongly believe in right to repair, have worked for both official repair departments, and third-party repair companies. The repairability of this unit is 5 out of 10. Should I try this myself? Sounds like the adhesive is the worst part. I’ve successfully removed and replaced the battery on my MacBook Pro so I know how crappy the adhesive can be. But this close to the screen…worries me a bit. Also, does iFixit still sell the adhesive/tape and/or kits containing all the tools and parts you need for this? I really wish companies would stop using adhesive. Anyway, thanks for reading!

The single thread like line is one of the thin Metal Oxide traces on the glass plate of the LCD panel which drives the panel has become disconnected. We can it a TAB error Defective pixel - Tape Automated Bonding fault Sadly, there is nothing you can do to fix this and you didn’t create it from the environment of your shop. One way this can happen is when the wrong tools and technique is used to remove the display assembly. Going to far with a sharp tool or prying are often the cause where the glass is stressed causing micro-fractures within the thin Metal Oxide traces.

Addressing your storage question: Apple did their own thing! While the Fusion Drive SSD is a blade type it is not pin compatible with the M.2 standard! Its unique to Apple. As for which to replace the blade SSD offers a faster I/O being PCIe/NVMe x2 which gets you 5.0 GT/s Vs the SATA III (6.0 Gb/s) interface your HDD is using presently. Here’s a great reference The Ultimate Guide to Apple’s Proprietary SSDs So… If you need performance I would go with the blade SSD but its costly! So is there a middle ground?? Yes! The best config is to use a 500GB/1TB blade SSD and keep your HDD or replace it with a SSHD drive if you need a lot more storage. Thats if you want everything internal. Most pro’s go with the blade SSD and then use an external Thunderbolt drive either a single SSD or a RAID drive SSD array if you need massive storage.