Chosen Solution
Hi everyone! Hopefully someone can help me out. Today I replaced a 1 TB HDD for a 500 GB SSD in my iMac 27” late 2012. Since a read a lot before I tried it myself, I was very careful during the whole procedure. Unfortunately, since the replacement is done I have single a 1 (or 2?) pixel-wide vertical purple line in my screen . I was searching the internet and read a lot of different stories about the possible defects which can occur. But still not sure which is most likely: LCD defect > I was really careful with my screen, so can’t imagine this is the issueCable defectDamaged connection > checked all the connections, but none seemed damagedSoftware problemGPU problem? > however, when streaming via Apple TV, no line is seenOther? Can someone please help me out? Thanks in advance! Pepijn
Sadly you damaged the display assembly when you where removing it. I suspect you didn’t use the pizza cutter tool and/or pried along the side. You basically damaged to tiny wires that connect to the LCD. Your only hope is to replace the display - Sorry ;-{ Update (01/07/2018) OK, why am I’m sure sure you damaged the display. First I’ve killed two my self ;-{!! I wasn’t using the tool at the time just a blunted knife (the tool wasn’t available at the time) So I know how delicate the panel is. So where are these small wires? The wires are within the glass layers of the display and exit at the edge where a cable assembly brings them to the back (this is what you damaged). Think of how the fabric of your shirt is made by the warp and weft lines (X-Y) this is also true with a display there is a set of lines which go left and right and another set of lines that go up and down. So damaging any one of these interconnections creates a dead row or column.
I had this problem after replacing a HDD. Resetting PRAM fixed the problem. Whew! I thought I messed up a screen.
