Purple Hue on the edge of the Screen after SSD UPGRADE

How do I check the video connector? Do I have to open up the Mac again?

Hi Rama

The video connector for iMacs is generally a 30-pin wide gold plated connector coming from the back of the screen to the main logic board. You'll want to check for bent pins on the cable and damage to the connector on the board. Making adjustments to this cable could fix your issue if there is no physical damage to the LCD panel/Screen Assembly itself.

@refurbpro - LVDS signaling was used in the older iMac's (2011 and older). When Apple went with the thinner iMac's they switched to iDP (eDP) signaling which is like the difference between analog TV Vs digital TV.

The haze issue you might encounter within LVDS connections just doesn't happen here with iDP.

Here's a good source of display defects Sony T-CON training manual as well as iDP (Internal DisplayPort) Technology Overview & DisplayPort

@danj I really appreciate the info! I can only suggest solutions that have worked for me in the past, but I'm always willing to take a deeper look.

@refurbpro - Most haze issues I've seen on the newer models tend to be either image persistence issues or pressure marks from the act of taking the display off around the edge areas. Both issues can be fixed by new screens.

Seeing a picture or two would help in ID'ing which was the cause.

@oldturkey03 - I've never seen the LED's alter their color other than yellowing from burning the reflector plastic.

Can you expand how the backlight LED's alter their color here into the Blue spectrum, The only thing I can think of would be the driver voltage being too high not the backlight in the display its self. Yet I've not seen this in all of the systems I've fixed.

@danj that is absolutely great to hear. I am so thankful you never had to deal with that. Outstanding.

@oldturkey03 - I was serious! Can you expand what was the issue.

@danj let me try to explain this in my simple minded ways. As we all know LEDs’ do not directly produce white light. There are two ways in which white light is produced from LEDs’ . One (most common) is using a blue LED with a phosphor coating to convert blue light to white light by a process called fluorescence. The other method is by using RGB LEDs’ to produce white light. White light is produced by varying the intensities of the individual red, blue and green chips. The vast majority of LED lighting  are of the PC (phosphor coated) package type. It is known that LEDs’ phosphor coating method will, with aging, demonstrate curling of the phosphor relative to the LED chip. It is this curling that cause a spectral shift toward blue.  Another coating method is known to cause a shift toward yellow as high temperatures cause air gaps to open up between the phosphor coating and the LED chip, which is called delamination.

 A major part of the challenge is due to the LEDs’ sensitivity to temperature changes. The chips naturally run hot, and without adequate temperature control, overheating occurs and performance will rapidly degrade. Yes, newer LED packages have modified the earlier PC method to address the ‘curling’ and ‘delamination', yet color shift will still occur as a result of factors such as age, overheating etc.

So, I am never surprised to see that a LCD panel eventually shows a blue/purple or yellowish tint. But that is just me so I am really glad to hear that you never encountered this.