Chosen Solution

My iMac suffered of the infamous dust between LCD and backlight problem. I decided to follow the advice given in this post. Everything seemed fine, I got rid of the dust, until I reassembled to whole device. Upon turning it on, the screen showed massive artefacts, especially horizontal lines, making it unusable. Here are links to a few screenshots: Desktop Whole display just after turning on Cmd-V startup I have triple checked all connections, even tested the LVDS cable’s connections with a multimeter, and everything seems fine. The LCD model is LM215WF3(SL)(A1) Any help is much appreciated, thanks!

From your pictures it looks like a TAB fault (Tape Automated Bonding). A TAB fault is caused by a connection failure from the TAB that connects the transparent electrode layers to the video driver board of an LCD. If you moved the LCD logic board in a manner other than gently opening it like a flap you more than likely have compromised the connections between it and the glass, the TAB. The wires in the TAB/ribbon cables that attach the logic board to the transparent electrode layer on the glass are about half the size of a strand of hair. They are very fragile and their exact placement is critical. If the TAB is broken you need to replace the LCD.

I’ve talked to several people at Apple on the screen problems and they are well aware of them but are keeping closed mouth about it for now. I’m pretty sure we will either see a class action suit against them shortly or they will fess up on their own. Regardless of what you end up doing, keep records to turn it for reimbursement. As to trying to get back working let’s see if we can isolate the problem. Hook it up to an external monitor and see if the problem persists. What did you use to clean it and how did you go about doing it?

I am familiar with that post. The instructional video has been deleted. This is part of my notes:…. 4 cables that attach the LCD panel to the boards. Remove them, but be very careful, especially with the wide flat cable that’s close to the middle of the screen - it’s very easy to damage that connector… The other thing that comes to mind is how wide did you open it? My understanding is it was best to open it as little as possible.If you opened it up to far you may have hurt the connections to the actual LCD.