Dark Image Artifact on Screen

I have a 27 inch Apple Thunderbolt that I purchased new, about five years ago. Shortly after the extended AppleCare warranty expired I began to notice dark vertical image artifacts in the screen. These artifacts were especially noticeable when I would change the desktop wallpaper to a single, dark color. I have included a photograph taken today (some eighteen months later).

When I first noticed this problem, I called Apple Support to enquire about whether there was a fix, and how much. I had earlier purchased a late 2011 MacBook Pro that had died due to a now-famous problem with the graphics chip. Fortunately for me, Apple authorized a local service center to repair the MacBook with a new mainboard. It seemed that Apple had issued a 'silent' recall on the MacBook problem. I was hoping for similar luck with the expensive (>$900) display. No joy! Apple told me that the display panel was probably at fault, and it would require replacement; a very expensive proposition for a 3.5 year-old monitor. They also told me then, that they had decided to discontinue selling displays. Effectively I was S.O.L.

The artifact effect has been slowly getting worse, and while it doesn't impede my ability to work on the monitor, it is distracting. I did a little research on these 'artifact ' images' on 27 inch Apple displays last week and found several postings on YouTube where people removed similar problems from iMac displays by removing the display panel, separating the backlight from the display element, and cleaning out dust deposits trapped within the display panel itself. I tried this fix but it did nothing to remove my display artifacts.

I suspect that the origin of this problem is heat damage to the LG LM270WQ1 SDB3 panel used within my Thunderbolt Display. This thing was designed while Steve Jobs was still alive and running Apple, and it is well known that he had a nearly obsessive disdain for cooling fans in Apple products. The Thunderbolt Display has only one cooling fan drawing air through its enclosure, over a convoluted flow path, that appears to bypass the region where my artifacts now appear.

I really don't want to give up on this display because (1) it still works, (2) it was freaking expensive, (3) I don't think that something this expensive should be limited to only a lifespan of three years. However, I am trying to get a writing project done before July and I am literally staring at this problem for 10~12 hours per day! I am considering just kicking the Thunderbolt to the curb and buying a similar monitor from Dell or Asus (at less that 50% what the Thunderbolt costed). I have tried replacing the cooling fan, cooling fan temperature sensor, and power supply board with no improvement. What I am looking for here are suggestions for what else I might try to get this problem to go away. I know how to solder and perform fine electronic work and I am not timid about opening up Apple products to affect repairs.

I have included a picture of the image problem in its current state and a few shots from last weekend's attempt to clean the panel. In closing, I am increasingly becoming soured on Apple and their products. I 'switched' about twelve years ago because I couldn't stomach what Windows Vista offered and Apple had an image for producing higher quality hardware. After the late 2011 MacBook Pro debacle and this Thunderbolt Display breakdown, I am increasingly skeptical that paying more money for Apple products that only irreparibly break down after three years (the maximum AppleCare warranty) is justifiable. Apple's apparent policy of ignoring/denying design flaws in their products or flippantly advising customers to 'just buy a new [iPhone/iPad/MacBook ... etc.]' isn't doing anything to build my confidence in their company or products.