Chosen Solution
Hi there. After following different tutorials here, I decided to upgrade my iMac 27" late 2013 with a new SSD. But, unfortunately, when mounted the display assembly back the image is scrambled - I can barely see anything. Backlight is goodConnecting an external monitor shows the image properlyChanged LVDS cable and shows the same thing. But, weirdly, after changing and reseating the cable once or twice, image appeared, and after a restart, disappeared again.Cleared PRAM, and all sort of stuff I believe it might be the display assembly, but just wanted to ask if someone had this issue previously, just to make sure I don’t buy a new display assembly and then figure later on the problem is the motherboard. Below is a picture of what I’m seeing:
Any thoughts?
You may in fact have a bad SSD unit if you put in the blade SSD on the backside of the logic board. Unlike the HD it has a direct connection to the PCIe bus so if its bad it will play havoc with the rest of the system. If you had just swapped out the HD for the SSD, then I would say you put the iDP cable in backwards (FYI Apple changed the displays interconnect technology in ‘12 from LDVS to iDP in the iMac’s) Update (09/21/2016) OK, so you just swapped out the HD for a SSD. And now you’ve double checked the direction of the cable. So lets try this with the display not connected, connect an external display to your system does it work? Also FYI you do need the OWC In-line Digital Thermal Sensor for Hard Drive Upgrade for 27" iMacs 2012 and Later otherwise your systems SMC services will go wacky here. I don’t recommend using software over-rides!
