Chosen Solution
I bought old 27" Apple LED Cinema Display recently with well known problem of screen flickering on higher brightness + sometimes (not all the time!) washed colors/light leaking on right upper corner. I opened it and it was clear right away, that connection on left LED strip is very loose and broke completely when I touched it. I thought that backlight leaking on right side is connected with this. I ordered spare pair of LED strips to LM270WQ1 (used ones only available), dismantled LCD panel, replaced both LED backlight strips successfully and mounted panel back. To my surprise: when I finally connected it to computer, backlight is working without any issues on highest brightness setting but unfortunately the right upper corner has still washed colors/backlight leaking. In addition I can see some image persistence as well.
Any clues what is wrong? Anyone had similar issues?
This looks like the defused sheets got messed up and may be damaged. There is also an order in the sheets so the full display gets even illumination from the backlights. For the dark corner this might be a few dead LEDs in the string.
