Previous 1 2 3 Next 184 Replies Latest reply: Jan 26, 2016 12:49 AM by WeRepairTech ltd Branched to a new discussion.
Kaos2K Level 1 (0 points)

If you have a Late 2009 27" iMac and are having problems with those annoying problems of flickering and parts of your screen are becoming darker (On the left side primary) you may want to consider this easy guide to fix it if you run out of warranty, have no Apple Care and Apple wanted to charge you about $600 to replace your screen. You need no tools and the cost os this procedure is 0.



First Step: Be sure that you are experiencing the same symptoms



This guide is only to resolve flickering and dimming problems on you iMac screen. Primary occurring on the left side (becoming darker or with less brightness than the other side) and on Late 2009 27" iMacs but there are cases of the same problem on later computers too.



Check/Read all of these posts to know if your case is the same:





Thanks to the findings of nicholasfromconfolens we know that the problem resides in some parts of the screen getting loose for any reason (factory problem, heat, whatever) and if you apply pressure at certain point the flickering/dimming/darking disappears. The problem is that you need to maintain that pressure all the time.



Second Step: Find the correct spot to apply pressure



Without removing the glass panel of the iMac, try to press it strong enough (but don't use excessive force or you could break it) near the bottom left part to see if the dark/flickering disappears at some point. If it does, you are lucky, your problem has easy solution and you can proceed to the next step. If not, don't despair, your glass panel may be very strong and you will need to remove it to apply pressure. Head to the next step.



Third Step: Removing the glass panel



It is recommended to use suction cups to make this task more easily but it's not mandatory, you can remove the glass with your hands. The glass panel uses magnets to get in place all around and has some flaps on the bottom part. To remove it you need to hold it from the upper right and left corners and make force towards you, once it get loose just elevate it to remove the bottom flaps from its holes. You can follow these links with guides that clarifies this a bit more:






Fourth Step: Pinpoint the correct spot to press and place something to maintain the pressure



Once the glass panel has been removed, you must find where is the best point to apply pressure to get rid of the dimming/darking/flickering. The most common point is the left side between the rubber band of the screen and the grey band below. (See the photos for better understanding).



Once you find the best spot, you need to place there something to increase the thickness in that point and to maintain pressure when the glass panel is mounted again. I suggest you to use a pair of adhesive strips/pads mounted one over the other made of rubber or textile material that are used to put under furniture (chairs, tables) to prevent them to scratch the floor (I don't know the exact name in English, sorry).



Fifth Step: Mount the glass panel again



Mount the glass panel again and see if the pressure is enough to prevent the problem appearing again. If not, you should dismount the glass panel again and add more thickness to the "critical" spot adding more pads, but beware, add them gradually or the pressure may be excessive and break the glass when you remount it.



Final Step:



Enjoy your "new" screen and the saving of nearly $600 on repair costs.



Here below you can fin some photos and a video of my "set-up" to fix the problem.



Foto 19-06-12 14 23 56.jpgFoto 19-06-12 14 25 09.jpg

Foto 19-06-12 14 25 17.jpg

Foto 19-06-12 14 29 33.jpgFoto 19-06-12 14 29 19.jpgFoto 19-06-12 14 31 12.jpg




iMac 27" (Late 2009) Flickering And Dark Screen Fix (VIDEO)




I hope this guide helps you. Feel free to contact me if you have any questions.

iMac, Mac OS X (10.6.4), No tools required
  • BDAqua Level 10 (122,202 points)

    Great post, thanks, have bookmaked it dor referrals, thank you!

  • Kaos2K Level 1 (0 points)

    Ok. I think i have found the real root of the problem that causes all this flickering and darneking on the screen and why applying pressure works sometimes but it's not a permanent solution


    There is a LED connector on the rear side of the screen (You need to remove the display from your mac to access it) located at the lower right corner (left corner if you look at the screen from the front) that may be causing all this trouble. It is hidden beneath the sticky silver paper and adhesive strips. The pins of this connector (both board or cable ends) may be loose, broken or not well soldered due to the stress, heat or whatever. This causes that power is not reaching the LED lights on that part of the screen and therefore, the dark corner and flickering when they are making contact and suddenly they are not.


    I removed the connector completely, connected the screen again and power up the iMac and guess what? It booted up correctly with no errors but with the dark corner being permanent.


    The solution is to fix the connector by soldering it correctly (maybe just a small push would solve it for you) or soldering the cables directly to the 6 points needed (The bigger two of the sides appears to be just physical anchorage for the connector). I'm currently doing that now. I'll update this entry with my results.


    Meanwhile you can you can watch this video/photos i have just uploaded for you to see:


    [VIDEO] iMac 27" (Late 2009) Flickering And Dark Screen. Faulty connector in LCD-LED.




  • Kaos2K Level 1 (0 points)

    Confirmed, i fixed the screen problems permanently by removing the faulty connector and soldering 6 wires directly to the points that you can see in the photos.







    My iMac's screen brightness is now better than ever.


    And finally, i made a custom wallpaper with the photos i have taken when my computer was open .



  • John-Paul May Level 1 (20 points)

    Kaos2K .. this is utterly incredible.


    How can I thank you enough?


    Just as you say the "pressure" solution is not reallya full solution. (I could never get it to work reliably in my case.)


    I am going to go try what you say !!!!!!


    Really, thank you so much for your time.  I am going to add links to your "full welding solution" here on the many places that address the issue.  Thanks again.  Thanks.

  • Kaos2K Level 1 (0 points)

    You're welcome

  • Katya1602 Level 1 (0 points)



    Great thanks to you, Kaos2K!


    I repaired my iMac 27 2011 yesterday. It was very tricky, but the result is there :-)


    I made some pictures of the process and posted them on Flickr:



    (I used the localisation picture you made, because I forgot to take the picture).



  • Kaos2K Level 1 (0 points)

    I'm happy that you have resolved the issue . I hope that my guide helps all the people out there that Apple left behind...

  • MichelPM Level 6 (11,351 points)

    Really awesome job and many thank yous for the excellent written and photo procesural documentation.

    You did a very thorough job!

    I bought a used 2009 27 inch screen model a few months, ago. I don't have this issue, but if and when I do, I have this posting bookmarked for the future!

  • cYrEaD Level 1 (0 points)

    Kaos2K, Katya1602,


    thanks for this.  When I removed the little problem plug, the white socket or female piece came right out with it - that white surface mount plug wasnt even really attached!  Apple needs to issue a recall for this production design flaw with the LG screen.


    but then I couldnt solder inside that tiny hole!  i tried with a magnifying glass and the finest tip I could get for my iron -but it just wasnt happening.  I tried bending the contacts on the white socket that came out so that might make better contact - but no luck. 


    anyway if you're willing to pass on your solder technique I'm curious.


    guess Ill take it in to the apple store so I can pay for a brand new screen when my computer is only one month out of one year warantee.  Crazy. 

  • John-Paul May Level 1 (20 points)



    "When I removed the little problem plug, the white socket or female piece came right out with it - that white surface mount plug wasnt even really attached!"


    You know what, in many cases it might be best to NOT PULL OUT the white female socket.


    I have very fortunately completely solved the problem in my case by just GIVING THE PLUG A PUSH -- it was just that simple.


    I had the mac RUNNING so I could see the results of tapping the plug.  the solutin was nothing more than giving it a tap in the correct direction.


    I can NOT BELIEVE that there was the idea of a €970 panel replacement ... for a loose plug. That is just evil.  It would be literally exactly like throwing away a €1000 TV set, because the power plug on the wall was loose.


    Again, in my case - by simply tapping on the loose plug - I fixed it.  I added a tiny piece of cork on the back, with a piece of tape, and that provides a little more pressure to push it in.


    TBC, I was able to easily fix it by having the display out WHILE THE MAC IS RUNNING.


    You can get it so the bottom of the display is lifted up an inch, while the mac is running.  That is to say, I DID NOT disconnect the various cables that connect the display.  With the Mac ACTUALLY RUNNING, it is extremely easy to see that the cable is just loose, and a trivial push makes it work or not.


    (I guess the "full solution" is to completely take the display out - ie, disconnect the various cables and take it completely out -- and then perform a welding fix.  in my case I did not need to do this. the whole problem was literally nothing more than going "tap" with my finger.)


    I did this last nite and I will post a video ASAP


    Here is my exact procedure for fixing it:


    1. stand mac up normally

    2. put fingernails behind top of screen cover, pull sreen cover off

    3. lay mac down on rear

    4. remove the eight (8) useless screws

    5. stand the mac up again

    6. the display comes out at the TOP.........

    7. very simply lean the mac forward, and the top will ease out


    as there are a number of short cables inside connecting the display

    9. keeping the top out, lay the mac down on its back

    10. now ease the bottom of the display out (again only two inches all round)

    11. now put the TOP in, and using say an iPhone, wedge the BOTTOM open a few inches

    12. plug in the power and let the mac start




    it is at the extreme bottom left of the display towards you.  ie get down onthe floor and look up at the underside of the display and you will see it.


    Carefully rip off and throw away the stupid silver tape covering the problem plug


    it's now incedibly easy to fix. with your finger, gently tap or push on the faulty loose plug.


    in my case a tap fixed it - I added a tiny wedge (say a pirce of rubber) to put more pressure on it


    I just didn't bother replacing the pointless eight screws in point (4) above.  Slip the display back in, stand it up, put on the glass cover and get back to work.  It's that simple!  THANKS TO KAOS.




    1. remove glass screen

    2. lay mac down

    3. ease display out, but leave it connected and running

    4. have the top of the diaplsy IN the mac, and the bottom OUT, wedged up two inches by any object

    5. absolutely identify the problem area using KAOS' INFO

    5. carefully remove and throw away the stupid silver tape


    7. the whole problem is just a loose plug - tap it and you're done


    8. ease the display back in, put the glass cover back on (if you bother using the glass cover) and work away.


    that's the simple solution.  the "badass" solution is to fully remove the diusplay (ie disconnect all the cables that hold the display to the mac), and have a workshop fix the tiny broken plug)


    I'll post a video in a minute


    IT IS JUST A LOOSE PLUG .... it's that simple.

  • Kaos2K Level 1 (0 points)



    You can try John-Paul May's solution to see if that works for you and you can avoid the soldering. If not, the best technique to solder in that tiny hole (apart from the magnifiying glass that is a must) is to try to remove as much of the white plastic as you can, to make room for your soldering iron. I did it by cutting the plastic with a lighter-heated knife until i felt "confortable" to work in that space.


    Another useful tip is to apply a tiny drop of solder/tin in both the 6 board connectors and in each cable/wrapping wire you are going to use to solder to them. Then, with a lot patience, start heating the cables/connectors with the tip of your soldering iron as much closer of the tin drops as you can. I know this is not an easy work but it worths the time and the money saving...


    If you have more questions don't hesitate to contact me again

  • John-Paul May Level 1 (20 points)

    Here's the exact problem:




    1. remove glass screen

    2. lay mac down

    3. ease display out, but LEAVE IT CONNECTED and running

    4. have the top of the diaplsy IN the mac, and the bottom OUT....

    4B. ...use any plastic object to hold open the bottom - see photo

    5. absolutely identify the problem area USING KAOS' INFO

    5. carefully remove and throw away the stupid silver tape


    7. the whole problem is JUST A LOOSE PLUG - tap it and you're done


    8. ease the display back in, put the glass cover back on (if you bother using the glass cover) and work away.


    for DETAILS read two messages above.


    {it is commonplace to slip the screen out of an iMac, to swap the hard drive. if you have not done this before: remember that you can only take it out A FEW INCHES - there are a number of cables connecting the mac and the display unit.  Apple made these cables quite short, so, you can only ease the display out A FEW INCHES.  you can find many, many detailed explanations on the internet, how to slip the screen out.}


    that's the simple solution.  the "badass" solution is to fully remove the display (i.e. disconnect all the cables that hold the display to the mac), and have a workshop fix the tiny broken plug properly using solder -- as KAOS was able to do, because he's awesome !









    in the video you will see my finger simply tapping the plug, and the problem completely clears, completely returns, completely clears, etc., depending on whether or not I am pressing lightly on the plug.


    I don't know about lawsuits etc. but it is utterly amazing that Apple will not fix this.


    It is completely incorrect to think the "display must be replaced".  It would be like saying, you must replace a whole washing machine, because the 25-cent power plug on the wall happens to be broken.


    I will say this, it is ABSOLUTELY IMPOSSIBLE that Apple DO NOT KNOW the problem is simply a 25 cent socket.  Any technician, upon opening the case, would instantly look at it and say "oh look, the power socket on the bottom left is loose"


    Note that in some cases you may even be able to fix it WITHOUT removing the stupid metallic tape that hides the plug.  ie, simply pushing a little on the tape in the right spot, might make it connect.  the only "real" solution is to re-engineer the socket, as KAOS did. (The problem appears to be the tiny socket, rather than the tiny plug.)


    Thank you again KAOS for saving the day here.

  • Kaos2K Level 1 (0 points)

    Excellent! The more info we show about this problem and how to resolve it the more ashamed Apple must feel for not addressing it or offering a free solution!

  • John-Paul May Level 1 (20 points)

    normally an iMac display tilts OUT two inches, with the TOP out two inches and the BOTTOM in.


    ease the WHOLE THING out, and put the TOP in with the BOTTOM out.  use some object to hold the bottom open.  so it looks like this:






    again to be clear, the many short cables which connect the display to the iMac are still in place. plug in the iMac power plug and the machine will run completely normally.


    be very carteful when doing this, because you could scratch your work table with the sharp edges of the iMac stand.


    here is the exact problem.  look for the flat black cable on your left. There is a piece of silly silver tape over the flat black cable in question. Remove the tape carefully (ie, being careful not to further pull-out or damage the plug)





    notice the flat black cable on your left in this photo (running up and down in this photo).


    to repeat, that piece of flat black cable is covered by some silver tape - remove the tape slowly and throw away the tape


    And here is the entire source of the problem with LG display units in iMacs ...


    the tiny socket/plug where that flat black cable enters.  (I have small fingers and you can see how small the socket/plug is.)  this phioto is taken "from the floor upwards"  ie, I shoved the iPad inside the open iMac so that the iPad front camera was pointing upwards.




    if you watch the "dramatic video" in the previous post above, I very simply tap that connection on/off with my finger, and you will see the display become completely normal / dark / normal / dark, as I move my finger on and off.


    it's just that simple.  it is a real tragedy that this has cost many people $1000+ for a new display unit.


    the "full solution" is to re-engineer the badly-made, badly-installed socket using soldering -- SEE HOW KAOS DID IT IN THE ANSWER ABOVE.


    in my case, by adding some pressure it fixed the prblem.


    so I simply got a small piece of wine bottle cork....






    about half the size of the smallest piece you see there.  i taped it over the problematic plug with a piece of sellotape.  there happens to be a large flat piece of plastic, in the iMac, behind the problem area, so, the cork simply pushes against the plug


    (I do not know if fine Spanish Cork, that is to say Quercus suber cambium, is the ideal material to use here, but it seems really perfect - firm yet gentle.  If it bursts in to flame, I'll have to replace the piece of wine cork it with a piece of pencil eraser, or whatever.)


    if I can find a workshop that will do the soldering job, I'll just take the Mac in and happily pay a technician to fix-up the micro-plug in question properly.


    once again, to replace the whole LG display unit here, would be just like replacing a whole $1000 refrigerator, because, the 25 cent power plug on the wall is broken.


    result -- €1,000- saved.  thank to KAOS.

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