PLEASE MAKE THIS THE LAST POST about this!
This way other people can know that IT IS POSSIBLE TO FIX (DIY) THIS PROBLEM!
This is for all iMac users that are out of warranty & can't afford buying a new LCD module.
I hope this message will not "mysteriously" disappear.
If it does we'll know that all these discussions are being watched & censored.
By 04:30 of the only video-repair of a (late 2009) 21.5inch iMac (http://www.youtube.com/watch?v=GONDMj0Glt4) I felt really desperate because I had the LCD split apart from the iMac's body with all its adhesive tape strips opened but it didn't seem to make a difference: the **** panel seemed solidly attached to its frame & there didn't seem to be anything else I could do! I didn't want to force anything, risk breaking some component & ruining my just-bought (2nd hand) iMac 21.5''!
So, as I had to guess it the hard way due to the lack of that part on that video, I will now explain my 10 steps so that no one else has the difficulty I had to accomplish this fix:
01 Slip a clean folded sheet under the iMac.
02 Get yourself a strong suction cup, apply it to the upper left or right corner of the iMac's & pull out the polycarbonate front.
03 Remove the 4 left + 4 right torx T10 screws around the LCD & copy their positions on the iMac onto the surface you'll lay them so that you later know which screw belongs to which hole. Sometimes screws want to be returned to their usual house. I must say already that, on my way back, this was what didn't turn out perfect: the holes on the right side (& just on that side) didn't match; they were like 1 or 2mm offset & the screws had to be half-screwed & inclined.
04 Pull the LCD out & incline it about 20 degrees from the iMac's body, just enough for your hands to slip inside the gap for you will have to disconnect 4 cables. You might want to ask someone to help you by holding the LCD from behind the iMac.
05 Disconnecting the 4 cables (#1: vertical sync | #2: backlight power | #3: display temp sensor | #4: LVDS) that link the LCD to the iMac's body:
Pay attention to the points where the cables connect or photograph them so that you'll know how to restore it on your way back.
Be very careful & patient for these connections are delicate!
The upper left one (#1) is a thin blue-tip strip that you have to pull to your right, the bottom left black one (#2) you have to gently pinch & pull both tabs down and the other two you must squeeze the sides to release.
Take your time.
06 With the LCD separate from the iMac's body, place it over the sheet with the front down.
07 Remove the 2 left & 2 right screws, from the sides that are shorter. 1 screw in each side is hidden under a little adhesive cushion that you must partially lift up.
08 Start opening/lifting (not removing) ONLY the adhesive tape strips that are helping bonding the LCD Panel to the frame. There are several sorts:
- aluminum/tinfoil mylar
- fabric-like
- black thin plastic
- black thick rubbery copper square
09 Detaching the LCD panel from the frame:
Use a plastic or latex glove on your left hand (if you're right-handed) so that you don't stain the LCD's front.
You might want to try pressing the other side of the LCD panel upwards & verify it doesn't even seem to move. Don't get frustrated & don't spend a lot of anguish time (like I did) searching for some hidden screw or anything else that you might have missed. Understand that the LCD panel will only move up through the frame after you force it to. It is still attached to the frame by 2 left + 2 right tiny white tabs and 5 black ones on the bottom side — if you don't see these 5 it's because you haven't lifted the longest mylar tape strip enough.
If you are sure that you have removed all the 4 screws & lifted all the tape strips that covered the narrow gap between the LCD & its frame then grab your screwdriver (or something with a larger tough tip) & fit it on that gap beside a white tab that is closer to the corner beside the longest mylar tape strip. Force the LCD panel out of the frame while pressing it upwards on the other side with your other hand's thumb. Right after this place your screwdriver on the nearest black tab, push it down while pressing up the LCD panel & pulling the frame edges down with your nails. If you do it vigorously you'll start to see it come off!
This is the toughest part, specially if you do it alone, so it's a good time to remember the money you'll have to spend if you don't take that **** LCD panel out of that frame! In my case the price I was given from APPLE's assistance for the replacement of the LCD module was nearly €500, which was 90% of what I paid for my (2nd hand) iMac!
So be careful but PUSH, PULL, PRESS!
10 Cleaning the inside of the LCD panel:
If you got to this point: congratulations!
I didn't completely open/separate the LCD panel but just enough to be able to slip inside an anti-static cloth & gently clean that problem away!
Have a peek inside yours with lighting coming low from a side & you might recognize the forms of the stains that have bothered you for so long! It's dust that somehow, despite all the tape strips, gets into the LCD panel but I was too anxious to investigate it deeper, and the odds are that APPLE has no clue either. I guess that a removable dust filter before the fans could help…
So to prevent this you might want to avoid using your iMac in a dusty polluted room.
APPLE really deserves this tutorial for not having listened to (i)Mac-users in this & so many other problems!
This repair is NOT in this iMac's APPLE Technician Guide but, & here's a final thought, it's "funny" to verify how, after this fix, the LCD panel looks just as new...