Does my Cinema display need a new controller board?

[ACD30"]

I recently acquired a 30" Cinema Display — all is well, except for a small problem: there are faint vertical lines appearing on the screen. These lines are normally nearly imperceptibly faint; however, just today, I was greeted with an amplified case of the vertical-line syndrome. I do not have a picture, but I will link one of a display suffering from a similar problem. (Note: mine does not have the backlight bleed shown in the attached photo — it just has a less consistent and somewhat less severe pattern of lines when compared to what's shown below.)

Question is... what needs replacing? The last thing I want to do is chuck the display. If it's something as simple as the controller board, I will gladly buy a cheap replacement. However, if this indicates the LCD assembly is on its way out, or some integrated cable has malfunctioned... then, well, I'd rather save myself the cost and effort.

Suggestions are appreciated. Thanks!

 

[joevt]

Old age/corrosion. I think it can be repaired but it's delicate work. Probably cheaper to get a new display.

Use a red, green, blue test image to figure out which color(s) is broken.

With a white background, I have a single vertical yellow line on my display. This means one of the blue vertical lines of pixels is always off. The line will be black when using a blue background. The line will go away with a red or green background. Read the page at
https://forums.macrumors.com/threads/2011-imac-graphics-card-upgrade.1596614/post-29555360

Your issue might be different than mine. The pattern on your screen is too regular and doesn't look like it's a single broken line. I guess the test images could help characterize your display's problem better.

 

[ACD30"]

Old age/corrosion. I think it can be repaired but it's delicate work. Probably cheaper to get a new display.

Use a red, green, blue test image to figure out which color(s) is broken.

With a white background, I have a single vertical yellow line on my display. This means one of the blue vertical lines of pixels is always off. The line will be black when using a blue background. The line will go away with a red or green background. Read the page at
https://forums.macrumors.com/threads/2011-imac-graphics-card-upgrade.1596614/post-29555360

Your issue might be different than mine. The pattern on your screen is too regular and doesn't look like it's a single broken line. I guess the test images could help characterize your display's problem better.

Thanks for your reply — the issue my display was exhibiting was not quite uniform across the entire panel; I noticed that the streaks were confined to the left half of the display. Also, these streaks pinstripes were a translucent white, rather than black and/or colored; they had a sort of partial opacity that allowed for the contents of my desktop to be visible from "behind" them. This does not match the image I had attached: an example from some other case I had found online. (Long-story-short, the symptoms had cleared before I was done scouring the Web for possible explanations.) This probably was not the best example to use, admittedly. And so, this is why I've described the symptoms in further detail, here, and have removed the image I had attached.

Anyway, the display is currently back to 'normal,' meaning it is how it was when I had picked it up — seemingly flawless, except for a very faint pinstripe pattern that is only really visible over dark / black images.

 

[joevt]

I guess you have a back light problem, instead of a pixel problem. While it may go away after awhile now, it may become permanent in the future like the pixel problem.

I have a subtle horizontal pin stripe issue near the top of the display most noticeable in the top right corner. The lines alternate light/dark. It's more noticeable with darker colors (like with the light gray of a window title bar but not with the white of a window background).

 

[ACD30"]

I guess you have a back light problem, instead of a pixel problem. While it may go away after awhile now, it may become permanent in the future like the pixel problem.

I have a subtle horizontal pin stripe issue near the top of the display most noticeable in the top right corner. The lines alternate light/dark. It's more noticeable with darker colors (like with the light gray of a window title bar but not with the white of a window background).

Yes, the issue you have described is essentially what my monitor regularly exhibits. Typically, it's too subtle for a camera to pick up; however, I can certainly still see it with my own eyes, especially when the effect has increased in intensity.

Is there a trivial fix, or am I looking at a replacing the entire LCD assembly? Separately, might you have any reason to believe it could be an issue with the T-con board? From what I've seen, that can often mislead users into thinking that their backlight is faulty or has failed. The part is cheap to buy, so I'm wondering if I just order 'n swap.

 

[MarkC426]

As some people here seem to have similar issues, I might jump in with my issue....
ACD 23", got a single white horizontal line pretty much across the centre of the screen, many, many years ago.

Replaced it with a Dell, but never had the heart to throw it away.
Box and monitor are mint, cost me £1k when bought.

 

[ACD30"]

As some people here seem to have similar issues, I might jump in with my issue....
ACD 23", got a single white horizontal line pretty much across the centre of the screen, many, many years ago.

Replaced it with a Dell, but never had the heart to throw it away.
Box and monitor are mint, cost me £1k when bought.

When I was searching around for potential causes of the issues my monitor is exhibiting, I came across many results demonstrating issues similar to what you've described. I think it has something to do with the ribbon cables going to the LCD assembly (from the T-con board, I imagine). Apparently, people have been able to bandage the issue, by way of applying pressure to those cables. I have basically no expertise in the realm of servicing LCDs, though, so I cannot give any sort of technical explanation.

 

[MarkC426]

I just think the build quality is top notch, solid aluminium frame.
Surely there's a demand for spares, power supply etc.

Can't bring myself to just throw it.

 

[joevt]

I just think the build quality is top notch, solid aluminium frame.
Surely there's a demand for spares, power supply etc.

Can't bring myself to just throw it.

Maybe the power supply. I've had a couple of the 23" power supplies fail. Now I use a 30" power supply for the 23". The other 30" power supply for my 30" has never failed. So now I have two 30" power supplies in case it does.

 

[MarkC426]

Oh well my 23" will sit in it's box for a bit longer then.

 

[ACD30"]

I took a picture of the pinstripes I was referring to, over a dark background. My monitor has not 'freaked out' since I created the thread, though it has consistently been displaying these pinstripes — sometimes a diminished version, but typically at the intensity shown.