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Kaos2K Author

Level 1

1 points

[GUIDE] Fix iMac flickering and dark screen problems out of warranty

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.

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

Posted on Jun 19, 2012 8:37 AM

186 replies

Feb 11, 2013 10:41 AM in response to zaNabiT

hi,

Yes, the problem is fixed now. I did not manage to take photo when I was doing it, but i am sure we are happy to help here if you can explain to us how far to get to now.

i got to the connector, i tried gently pressing it, wiggle the connector, apply pressure with tape, nothing was helping. so i cut things up to remove the black cable (6 small wires) along with the white connector with you will see 6 teeth that stand straight up in the center and 1 smaller one on each side. that 2 on each side seems useless because you can see only 6 black wires. i used a small clipping tool and just gently bend the teeth so when i put it back it, it will have a better touch to the board.

yurikg1

Level 1

0 points

Feb 25, 2013 4:12 AM in response to Kaos2K

Hey guys,

I've got the same problem with my late 2009 iMac and I tried to follow the instructions from this thread - applying pressure on plug helped for only 2 days, then I decided to give a try with soldering option, but this place is TINY, I don't even know which soldering gun could be suitable for this, I bought one with pretty small coppe-bit, but it didn't helped. I made a big mistake by cutting the black cable (in order to connect it this with soldered cables) but it was too early. So I tried soldered it back and tried the solution with bent pins but it didn't help eirther :-(

I asked a couple of friends here in Munich, who even repair Macs, but nobody knows how to solder in this place, and workshops refuse to solder it, they say that only option to solder is, to disassemble the casing, but it's to much work for them.

Could you give me at least some hints how you did the soldering, it's actually the last option left for me, apart from buying the new LCD panel (and the new LCD panel will have potentially the same issue!).

Thank you in advance,

Yuriy

Kaos2K Author

Level 1

1 points

Feb 25, 2013 4:33 AM in response to yurikg1

I used a JBC 14ST soldering iron to do it.

The best technique to solder in that tiny hole (apart from doing it with 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.

It's hard but not impossible.

I hope this helps you. Good luck.

BTW: If you cut the black cables, don't worry. Those cables only carry power to the LED lights in the lower left area, your display still works except for the "no-light" in that corner.

MobaLA

Level 1

0 points

Mar 5, 2013 12:14 PM in response to Kaos2K

I have this problem with a 2011 iMac and tried to solder some cables to the connectors. Now it behaves strange: After booting the login screen appears with the same brightness all over the screen, even the left part works. But about 1 second later it just goes off and remains dark. Everything appears to be running correctly, only the backlight goes off.

Did anyone already had this problem?

Maybe I connected 2 cables by mistake but I couldn't find them yet.

Mar 14, 2013 2:12 AM in response to Kaos2K

Hey Kaos !!

Here's some exciting news .. have a look at this post ...

http://forums.macrumors.com/showthread.php?t=1151134

at one point they changed a stupid plug on the Controller Board, for no reason!

So, if you get a new panel, you may very ell have this problem.

(I was thinking "if only Kaos was here to weld this stupid little plug!" 🙂 Fortunately I was able to "merely" swap the controller boards.)

(Note for anyone new to the thread - I don't mean "the" plug that causes problems on these displays. What I mean is that if you buy a new display perhaps from eBay, to swap out ... crazily at one point LG changed a small plug on the controller board of the display; this will cause you a big heartache when you try to swap panels. Its incredibly silly of them to change an internal plug like that, meaning you can't interchange the old/new parts (they are identical unchanged boards).)

BTW here's a video showing the basic problem, for anyone new to the thread!

http://www.youtube.com/watch?v=4QJ4rqvn2G8&feature=youtu.be

Mar 14, 2013 2:40 AM in response to Kaos2K

Ok so I know of ONE MORE PANEL AVAILABLE right now in Europe, very cheap. (March 2013.)

You can find it on eBay, LM270WQ1 and it is being sold by zeytech.de who are in northern Germany.

They had two and I bought one!

The one I bought is an A2 variant (see here for discussion of controllerBoard plug variants http://forums.macrumors.com/showthread.php?t=1151134 )

Here's the box ... the surgery .. and amazingly the finished working result.

Essentially, I did not have the time (or skill !) to do KAOS' solution

So unfortunately I had to spend the money on buying a panel from eBay. (New panels from Apple ae way too expensive to make it worthwhile on a two year old computer.)

One note with swapping panels. Your new panel will not have the metal brackets around the outside. (These are just 50 cent bent metal brackets that are glued on the edges of the panel.) I actually just found it too annoying to pull the brackets off the unused panel, so, I just didn't bother. (To be clear it would take you maybe one minute to do this, I just couldn't be bothered.) So, I simply haven't bothered screwing in the new working panel. There is actually almost no need to screw in the panel on an iMac - they sit there fine behind the magnetized glass front, unless you need to tip your iMac upside down! I prefer to be ble to get in to the iMac at any time to swap the drive or whatever, so I personally have never bothered even putting the screws in. For this reason I just didn't bother even pulling the brackets off the other one (also, I don't like glue!)

And again, in my case since the LM270WQ1 panel I got from eBay was an A2, but my Aug2010 Mac happened to have a C2 ... I had to swap the controller board, which is annoying, but detailed at the macrumors link above. Again, the controllerBoards are utterly identical, but LG annoyingly changed a small plug used on them. For this reason, you have to swap the controllerBoard!! (I guess, if you could find the "other type" of cable, or a plug adaptor - you could do that. KAOS, you could probably swap the plugs I bet.)

All thanks to KAOS for properly figuring out this problem, saved me $1000. Thank you so much, really.

Mar 14, 2013 2:55 AM in response to John-Paul May

Here's the surgery and the finished working Mac, thanks goodness...

Mar 14, 2013 2:56 AM in response to John-Paul May

Fixed at last ...

Kaos2K Author

Level 1

1 points

Mar 14, 2013 4:22 AM in response to John-Paul May

Wow! I'm glad you finally fixed the screen 😉.

As for the black connector variant you pointed in the MacRumors forum. I can't really notice if the "pin-out" is the same as on the white one. If it is the same, a quick cut and soldering eliminates the need to replace the whole board 😝.

Mar 14, 2013 4:35 AM in response to Kaos2K

right !

" I can't really notice if the "pin-out" is the same as on the white one."

To be clear, I did NOT HAVE a male plug for the C2 "white" plug. I had only my "black" A2 plug.

The shape is very different.

So fo rme, I had to swap the boards. I guess this is easy enough: it is just scary (for me) to change the ribbon cable. But, thank God, it all worked out. (I guess the new Pope helped 🙂 Even though I'm not catholic, Francis loves all animals and computers!)

Thank you again, you are #1 ! I thought I would have to send you my Mac to Spain to have it fixed! I would have done it but I could not find cheaper than about €80 to ship a mac.

It is an incredible waste my other display is just throw out. (My children destroyed it playing with it when I took it out 🙂 ) All because of one loose tiny plug.

cYrEaD

Level 1

3 points

Apr 6, 2013 2:23 PM in response to Kaos2K

I tried to solder this myself, and didn't succeed. I got 3 of the wires soldered in there, but couldn't get the others because it was just too tight, even with the finest tip I could buy on my iron, a good well lit magnifying glass, pre fluxing the contacts, hours of meticulous attempts that ended up just making a mess in that connector socket...

Then I got ******. Worked my way up the service higherarchy on the tele with apple support. finally some regional service manager made me an appointment at the local apple store - 40 miles away in Anchorage, AK. Got to the apple store and was told I didn't have an appointment. Then was told (after turning the computer on and showing them the half dark screen and pointing them to this feed) that it would cost $600. I just said no - I'm not paying that nor am I leaving the store till they make it right. The manager came over and signed off on the replacement at no cost. Then I was told there was a 3 week backorder of 27" screens probably because everyone is having failures. eventually after carrying the giant f'n computer back and forth to the apple store 3 times it was replaced at no cost. And they did the seagate 1tb drive recall work as well which I didn't know about prior to that visit...

Apr 6, 2013 2:27 PM in response to cYrEaD

So glad to hear you got satisfaction !!!

It ***** that their response is so erratic .. they seem to be giving in more and more. Congrats.

the new screen is awesome huh? 🙂 Hurts my eyes it is so bright.

yurikg1

Level 1

0 points

Apr 7, 2013 3:56 AM in response to Kaos2K

I also tried to solder myself and Kaos even recommended the appropriate tool but I didn't succeed. So it's really frustrating, I asked many workshops here in Munich, but nobody want to solder.

And it's very hard to find appropriate replacement lcd (LM270WQ1 A2), Apple doesn't sell replacement parts to individuals (why not?) and neither the serivice providers do. And I'm sort of wary of buying some A/B-grades repaired parts from eBay.

I know that it's not the place for these sort of complaints, but this iMac has quite a bunch of issues and Apple's feedback is just frustrating, the lcd issue was very well known and a lot of people are affected, I paid 2.000 euros for this machine and after more of 10 years Mac experience it's definitely the last iMac and maybe the last Apple computer I bought...

Kaos2K Author

Level 1

1 points

Apr 7, 2013 4:50 AM in response to yurikg1

I'm sorry to hear that yurikg1. It is really difficult to find a store or workshop that wants to be involved in such delicate task and even if they do, the cost would be high. In my case, the fix took me a few hours but i think it worths the time.

Before attempting the fix i was looking replacement LCDs from eBay but the cost was prohibitive (350-400e + shipping) but still cheaper than Apple's official "fare" to get this fixed. John-Paul May was very lucky finding that panel at that low price 🙂. Maybe you can keep searching for spare parts until you get one that fits your needs.

Vali31

Level 1

5 points

Apr 21, 2013 12:40 AM in response to Kaos2K

so there is no recall afterall? my mid 2011 imac its starting to give signs aswell .. half screen getting a lil bit more darker than the right screen..

Why so many ppl have to complain about a problem and after 1-2-3 years apple to solve this.. u sped a fortune on a cool box outside and so much junk inside (no offence) . I had no recall for my stupid hdd drive and make that grumbling noise... and now.. the screen gets darker .. How its that possible after u spend 2000 euros on a **** mac??

[GUIDE] Fix iMac flickering and dark screen problems out of warranty