Backlight or inverter?

I have a problem with my 20" Cinema display. it's the older model. About one third of the screen shows a dimmed light. could it be one of the lamps or is it an inverter problem? Is there a quick way to find out what the problem is?
thank you
Ngr

I can think of no way to tell if a lamp has failed versus a failure in the inverter driving the lamp without disassembling the monitor and testing the individual components involved. But regardless the failure, the monitor will need to be taken apart to repair it. It is the same amount of trouble no matter which is the bad component.

Similar Messages

Backlight to Inverter Connection

The backlight went out on my 17" PowerBook so I purchased a new one that came with the pole leads soldiered in and the small plastic white connector that inserts into the inverter. The end of the connector has four holes but I think only 2 are required to make contact with the male prongs on the inverter. Unfortunately, I could not get this connection to work. To make sure the backlight works I bypassed the white connector by having the wires make direct contact with the inverter poles and it lit up just fine. Thus, it looked like contact was not being made so I purchased another white connector and tried it, also with no success.
Did Apple use a custom plastic white connector that inserts into the inverter board for this model?
Thanks

Doubtful if anyone here has any idea. Contact the fake iPhone manufacturer.

Inverter or Backlight?

Hi,
I'm having a little bit of trouble with a new macbook that I hope you can help with... This morning I was just opening up an internet connection when the display became very very black (though intermittently a faint outline of the desktop could be seen). I thought I must accidentally pressed the light button (despite just using the mouse), but the display wouldn't return. The CD/DVD drive started making strange noises (despite being empty). I restarted the computer and the first grey screen appeared, as did a later blue screen, but everything else remained black. I left it on (still black) while I tried to search through the forums to find out what was going on. About 15 mins later the display returned, but all the desktop icons were missing. I relaunched the finder and everything seems to be fine now...
The posts I read seem to indicate backlight or inverter problems for this type of display issue.. how do I know which problem it might be and how to fix it?
Thanks!

As an update, this problem became increasingly worse. Two days after the first incident, the computer wouldn't display anything at all. After repeated attempts to run hardware checks, boot into windows, reset the PRAM it finally turned on for 5 mins, only to flicker on and off repeatedly every 60 seconds or so. It then turned off and I haven't been able to get the display back since (except for about 1 second everytime it boots up on the blue mac screen)... The weirdest part seems to be that it accesses the CD/DVD drive all the time.
I have now taken the computer to the nearest apple outlet for help... I can't believe this is only 1 month old! (The DVD/CD player has been crashing frequently as well - originally I thought it was bad CDs, but now I'm not so sure)....

Backlight turned off?

Hi there friends....
So, I have the blow post under my name re backlight problems. (Screen VERY dim)
Just wondering if I may have accidently turned it off? Is there a setting under display to check??
Chris

Can you adjust the backlight intensity using the F1 and F2 keys on your keyboard? If they don't do anything, try going to System Prefs -> Displays and changing the backlight slider there.
If that fails, it's possible that you might have a faulty backlight or inverter. It's best to get those checked out by an Apple Service Provider.
Hope this helps!

Early 2008 24" imac ram upgrade issues

Hi everyone. Hope you guys can help diagnose a problem I have with my imac.
It's an early 2008 24" imac with 3.06 Ghz processor and an NVIDIA Geforce 8800 GS 512 graphics card.
After buying Empire: Total War I thought it best to upgrade the 2GB RAM to 4GB, and purchased 2x2GB sticks 800 Mhz 6400 DDR2 SDRAM.
When they arrived I put them in and the system booted up normally. I could surf the net ok, but when it came to watching a video on youtube full screen, or playing a game, it would cope for 30secs-1min and then the spinning coloured wheel would show. I'd then hear noises that sound like a cd trying to eject then the system would hang. One of three things would then happen:
- it would automatically reboot showing the multi-lingual startup message that the system was not shut down properly
- a grey blank screen would appear and not change
- the grey start up screen would appear with the Apple logo and spinning circle, which would then stop spinning and not change.
If I manually rebooted I just get a black screen and can only hear the fans softly spinning.
I've tried swapping the ram sticks but get the same as above. It will boot and work normally with either one of the 2GB ram sticks installed on it's own. It will also work normally with the original 2x1GB sticks installed again.
I don't get the 3 beep warning at startup.
Any thoughts on why this might be happening? Would the graphics card be the reason for this issue?
I'm not sure if these are related but a few weeks ago I noticed that the brightness would randomly change from normal to half-brightness then back to normal. These would change every few minutes or so and isn't dependent on what programmes I have running.
I've also recently noticed that the top and back of the imac is getting quite warm to the touch and no don't leave the system running when not in use.

Hello,
Have you blown the dust out lately?
Get Temperature Monitor to see if it's heat related...
http://www.macupdate.com/info.php/id/12381/temperature-monitor
iStat Menus...
http://bjango.com/mac/istatmenus/
And/or iStat Pro...
http://www.islayer.com/apps/istatpro/
EDIT: you won't find iStat Pro at BDAqua's link any longer. (No longer supported by the developer, and not completely compatible with Mountain Lion, but most of its features should still be working.) It's here
https://www.apple.com/downloads/dashboard/status/istatpro.html
Do you have a link to the exact RAM you bought?
That grapics card is known to be a problem, but the brightness issue seems more like the Backlight or Inverter.

T61 LCD display flickering with big patches of black and going to dark (very low light) afterwards

I have a T61 which has Intel graphic card. It is seven years old and at times has a noisy fan.
Very recently it started to have problem with its LCD, it starts with slight flickering of light intensity from corners of screen, here and there, eventually covering the whole screen, goes away and comes back, happens for few seconds, the pattern repeats for few times, then big (screen-wide) patches of back starts to cover the lower 1/4th, one-half, 3/4th of screen, flickering between the screen content and black screen, till they cover the whole screen after 30-60 seconds. At that moment, the screen is very dark but with a close look, it is still possible (but very hard) to read it. Connecting it to external monitor (through its VGA), it is working very well. Showing same screen on both LCD and external monitor at the same time, the picture on external is solid, but picture on LCD can have this issue. At the moment of writing this message, the problem seems to not happening!! but it was happening during the past whole week including few minutes ago. I searched online and here in the forum and read few posts, and found about these issues:
- some T61's have Nvidia GPU and thermal effects over the time and stress on the package or solder balls can make loose connections (this is probably not my case since the interface to graphic card is by Intel)
- problem with LCD itself (it is working fine just right now)
- problem with graphic card (it is working very well over the VGA to external monitor)
- problem with the ribbon from mother-board to LCD (tilted the screen in different angles when the black patches and flickering are happening and didn't change the chaos much in any direction of making it better or worse)
- problem with bulb inside the screen (maybe the cause, but somehow decided for the last few minutes to working fine)
- problem with inverter (don't know yet what this part it)
- problem with some sort of mechanical part(s) being loose, gently tapped on sides and back of the screen while the phenomena was happening and again didn't have much effect on it in any direction.
I appreciate your time and good gesture of help, many of you would know more scientific/engineering ways of approaching the problem and how to root cause it. My sincere thanks beforehand.

> the screen is very dark but with a close look, it is still possible (but very hard) to read it.
That sounds like a defective CCFL backlight or inverter.
>- problem with bulb inside the screen (maybe the cause, but somehow decided for the last few minutes to working fine)
A CCFL is essentially a high intensity fluorescent bulb. One failure mode is flickering.
>- problem with inverter (don't know yet what this part it)
The inverter is a power supply that converts the low voltage DC used in the rest of the ThinkPad to high voltage to drive the CCFL. I would expect that to fail catastrophically rather than cause flickering.
What to do?
CCFLs backlights are relatively inexpensive ($10 to $15 on eBay) but they can be difficult to replace because they're delicate. You may prefer to replace the entire LCD panel assembly or even the entire top cover assembly (which also includes the inverter card.)
The Hardware Maintenance Manual for the T61 provides detailed instructions for doing this sort of stuff if you'd like to see what's involved and decide what you feel comfortable doing.
Cheers... Dorian Hausman
X1C2, TPT2, T430s, SL500, X61s, T60p, A21p, 770, 760ED... 5160, 5150... S360/30

Screen Light Off on the top?

Since few weeks ago the light of the screen (on the top) was kind of blinking at the startup in the morning, but after some minutes it came back to normal. And now, after beeing on sleeping mode for few hours, the top of the screen is quite dark as if the light on the top went off. So now I have a light degradé from light-bottom to dark-top. Is there anything I can do?
I work all day with it for photography...
(iMac OS X, with a 2.66GHz Intel Core 2Duo processor, from 2008)
Thank you! G.

Hi,
Either the Backlight or Inverter is going out.
http://www.ifixit.com/Guide/Installing+iMac+Intel+24-Inch+EMC+2111+Inverter+Boar d/5228/1

24" brightness gradient, color shift, or both?

We all know about the "issue". We've all seen the pictures and seen them in stores. However, I think I'm a little confused. We talk about some machines having a brightness difference and a blue/yellow tint.
Which one was the most concerning problem? Is it the brightness difference everyone is upset over (like this: http://forums.dpreview.com/forums/read.asp?forum=1017&message=27915616), or is it the slightly bluer left portion of the screen (setting a grey background and seeing the difference on the left side or seeing a yellower patch in the middle)? Or, are these problems one in the same?
In my case, the brightness is even on each side, except the left side does have the ever-so-slight bluer tint to it on about 1/3 from the left (you can be picky and maybe detect a slightly brighter left side too on a couple pics, but then again, so does my buddy's ACD at work).
I'm mostly for keeping mine, but to be honest, want to see if these issues are separate or considered one issue (the more brightness difference, the more yellowing, etc). The issues don't bother me during normal use and have to look for them to see them.
BTW, I took a boat-load of pictures here: http://public.ryanpetersonline.com/imac/
So are these two separate issues? Thanks.

rpeters83 wrote:
The Dell is a PVA panel. It also costs 1200 bucks!
Yes, the 2405FPW uses a PVA panel (Samsung LTM240M1-L01), but these
are certainly no more expensive than S-IPS panels used in 24" iMacs. Much
of the Dell's high price tag was due to the numerous deluxe features having
nothing to do with the LCD panel (multiple inputs, universal USB memory
card readers, 5-year warranty, etc.) Pretty good value compared to a 23"
S-IPS Cinema Display -- $1000 (including AppleCare) for ONE video input
and exactly ZERO features.
BTW, the current 24" Dell 2408WFP sells for $620 -- with an S-PVA panel
(Samsung LTM240CS05) and all the bells and whistles of the 2405 -- PLUS
HDMI, HDCP, and 110% color gamut. The ACD is a vastly overpriced fossil.
My main goal of this thread is to see if this type of mild color shift can happen
in LCD's other than the imac's. Perhaps the brightness of the machine brings it
out more than usual.
I've never seen a noticable color shift or brightness gradient in ANY of the
dozens of LCDs I've worked with. Pure speculation, but I wouldn't be at all
surprised if the problem is somehow related to Apple's irrational fetish for
"slim" profiles. Betcha a nickel Apple leaned hard on LG.Philips to invent a
thinner backlight/diffuser/inverter assembly. ...consequences be damned.
Looby

Problem with matrix/screen in Qosmio F55-Q502

Hello
For a few weeks I have strange problem with matrix/screen in my laptop.
The matrix flickers very often - no matter if power cable is plugged or not.
The screen is full bright and suddenly it starts to blink - it is getting darker, than lighter, usually for few/dozen seconds. It does it when nobody touches it or when I work on it.
It very annoying and making eyes tired - it does it very quickly and there are few levels of screen brightness.
Moreover sometimes the screen turns off - You can see what is on desktop but the screen is very very dark (but not blank or completely switched off). It happens without any reason - sometimes just in the middle of working, sometime for example when I touch (not pull) the power cable between laptop and power supply.
Then, the only way to get back to normal brightness of screen id to close the lid just for half a second and open it
- matrix lights then normally, but can "turns off" moment later and I must do it once again - sometimes even few times..
After "action" with lid screens seems like nothing ever happen..
Does anyone have idea what is the cause of such behaviour or how to diagnose it in details?
Or maybe solve this problem?
Best regards
300m

Sounds like the Backlight or Inverter is failing or there is a loose connection.
Is the unit under warranty? Send it to an ASP for repair.
You should avoid repairing it yourself, the backlight is very high voltage!

Length for Screen Repairs!?

I just wanted to get some feedback for how long a powerbook screen repair usually takes. Feel free to post first hand accounts about your repair process. I sent my powerbook in for a backlight power inverter repair and it's taking longer than I expected. Has anyone else had this repair done to their powerbook?

Did you get yours back yet? How long did it take? I have flicker on the bottom third of my screen. I am going to turn mine in for repair, as well. What I am most worried about is Apple replacing the screen and giving me one with bad pixels!

Print Preview does not work. I only see a grey color screen

This is a new problem that I haven't encountered before. I can't see print preview for any page. All I see is grey color from top to bottom.
Only if I copy + paste to MS Word I can see the Print-Preview.
There is no problem with other browsers such as Google Chrome or MS Explorer. Please help.

Hi Alex,
Hold a flashlight close to the screen at an angle & move it around, do you see a faint Desktop?
If so the Backlight or Inverter is bad.

Screen tinted in pink and turns blank. LiveKernelEvent 1033

Here's what the problem is:
1. The screen suddenly tinted in pink and turns black after 4-10 seconds. So I have to perform hard reset to reboot.
2. Nothing could be seen on the screen when I reboot but it would show up in external monitor, but there are vertical blue dotted lines on the screen and Windows would fail to start. It won't even get to the log in screen.
3. Rebooting again (using hard-reset) would bring me to Thinkvantage Rescue and Recovery startup repair and I can only fix the problem by restoring the system.
4. Then, Windows would be able to start like normal but the problem will occur again after 5-10 hours. Or else the screen will not turn on after I sleep or hibernate so I have to repeat step 2 and 3.
Today I performed a full restore using ThinkVantage Rescue and Recovery so the system has it's factory settings. Everything looks OK so it gives me a relief that was temporary. The problem will always occur again if I try to update the score in Windows Experience Index. After the screen flashing during the rating update, the screen suddenly tinted in pink or green and then blank so I have to repeat step 2,3 and 4.
Every video components passes when I tested the video card using PC Doctor 5. Sometimes after I restore the system, there is a message in Windows which sounds something like this: "Windows succesfully recovered from display adapter problem". I thought changing the display driver will fix the problem, but it will happen no matter what driver I used. I tried the newest driver that was released in 2009 (http://www-307.ibm.com/pc/support/site.wss/MIGR-67890.html), the older one released in 2008 and also the default factory driver released in 2007.Everything won't seem to work.
Update: I knew from Windows Problem Reports and Solution that it's caused by a hardware problem. Here's the details:
Description
A problem with your video hardware caused Windows to stop working correctly.
Problem signature
Problem Event Name:    LiveKernelEvent
OS Version:    6.0.6000.2.0.0.256.1
Locale ID:    1033
Files that help describe the problem
WD-20090712-0252.dmp
sysdata.xml
Version.txt
View a temporary copy of these files
Warning: If a virus or other security threat caused the problem, opening a copy of the files could harm your computer.
Extra information about the problem
BCCode:    117
BCP1:    83CF6950
BCP2:    8B337FC0
BCP3:    00000000
BCP4:    00000000
OS Version:    6_0_6000
Service Pack:    0_0
Product:    256_1
Is there a way to solve the problem?
Message Edited by gjoy993 on 07-12-2009 02:07 AM
Lenovo T61 Intel Core 2 Duo T7500
NVidia Quadro NVS 140M
Vista Ultimate 32-bit

Thanks for the reply. It is possible that the CCFL backlight or inverter board can stop working when I do certain things? (such as updating my rating in Windows Experience Index).
Besides, the problem happens to both laptop monitor and external monitor. The only time that only the external monitor shows something but the laptop monitor does not is when I reboot the computer (in step 2). After I restored the system, both monitors work as normal until the problem randomly happen again.
Here's some more info:
-The problem won't happen in safe mode
- I updated ALL the drivers to the most recent ones but it doesn't work
Message Edited by gjoy993 on 07-13-2009 12:19 AM
Lenovo T61 Intel Core 2 Duo T7500
NVidia Quadro NVS 140M
Vista Ultimate 32-bit

Safari window placement and size

New windows are opening with a different size and placement than I want. How can I tailor them to my preferences?

Hi Jack, not sure of course, but it sounds a bit like the Backlight or inverter.
Some things to try...
PRAM reset, CMD+Option+p+r...
http://support.apple.com/kb/HT1379
In fact, do 3 in a row, takes a bit of time.
Intel-based Macs: Resetting the System Management Controller (SMC)...
http://support.apple.com/kb/HT3964
One way to test is to Safe Boot from the HD, (holding Shift key down at bootup), run Disk Utility in Applications>Utilities, then highlight your drive, click on Repair Permissions, Test for problem in Safe Mode...
PS. Safe boot may stay on the gray radian for a long time, let it go, it's trying to repair the Hard Drive
Reboot, test again.
If it only does it in Regular Boot, then it could be some hardware problem like Video card, (Quartz is turned off in Safe Mode), or Airport, or some USB or Firewire device, or 3rd party add-on, Check System Preferences>Accounts>Login Items window to see if it or something relevant is listed.
Check the System Preferences>Other Row, for 3rd party Pref Panes.

Weird display crashes

I'm just posting this question to find out if anyone has experienced what's happened to my G4 recently. Waking it up from sleep mode, I've been working away and then - PHWATOINGG - the whole display goes BLACK! Just disappears. This has happened twice in as many days and I'm wondering if it's anything serious??
Anyone?

Hi, Dan. It's only serious if you need to see the display while you're working — otherwise, you can just ignore it.
But seriously: when this happens, if you shine a bright light on the display, can you dimly see whatever ought to be clearly displayed there? If so, what's probably happening is that your Powerbook's inverter, which provides power to the display backlight, is failing intermittently and needs to be replaced. And that is serious, because replacing it will cost a lot of money or a lot of your do-it-yourself time and energy, and the DIY replacement is anything but simple.
If there's nothing on the screen at all, even under a bright light, connect an external display to the Powerbook. If the external display works when the built-in display doesn't, there's a problem with the video cable from the logic board to the LCD panel or with the LCD panel itself. In that case the remedy will be to replace the entire display assembly, which includes the LCD, bezel, video and backlight cables, inverter, nd some other internal components.
If an external display behaves just like the built-in screen, your logic board is failing, and will have to be replaced. That's no joke either.
So unless you can be happy with a black screen, you're facing a considerable investment of money and/or effort in your Powerbook to get it running properly again. Whether or not that's worthwhile depends to some extent on how inclined you are to do the work yourself, as well as on which 12" Powerbook model you have. For a look at what might be involved, click on the appropriate 12" Powerbook button on this page.

21.5 inch iMac yellow screen issue

I have a late 2012 iMac (21.5inch). I thought 21.5 models were immune to this issue, but I noticed bottom half of the screen is showing some yellow tint compared to upper half. I thought it was due to the angle of the screen and lighting in my room but that changed when I put my MacBook pro right next to my iMac. Compared to my mid 2009 MacBook Pro, the iMac's screen has a definite yellower time to it..
How much will it cost to replace the screen to eliminate the yellow tint? Please, no replies about taking my iMac to Apple store or calling them. I've already called several different Apple stores, and they have no idea. And please, no Applecare answers or "expensive" answers. I just want exact numbers.

The in-store inspection, product specialist or in-house expert, then technical testing to diagnose the exact cause of the issue, then if done in-house, a repair sequence initiated with an open estimate on what replacement parts would actually be needed, could alter the original best-guess somewhat.
A simple backlight or inverter issue may be all that is causing the symptom. Nobody can simply give you a base price of one size fits all. They will not just 'replace a display' since the panel is more than just one part. If a voltage variation is the cause of partial tint or backlight color, then that will be part of the inspection and diagnosis; this may be in a shop for weeks.
Please stick to one question on the same topic
https://discussions.apple.com/thread/5919757?tstart=0
You appear to have an issue with Apple, so there are
a few good links to their main web site. You can go
and Locate an authorized service nearby, contact an
Apple authorized representative, etc, there. We who
reply here have no direct connection, nor do we have
any authority, cannot cite prices or give quotes, etc.
And our time is our own, individually. We're not Apple.
You will have to contact Apple. You have a computer.
I will not do that for you, from my residence, half a
world away where I have no more access to a Store
than a moose, or a ptarmigan, outside my door.
Good luck.

Backlight or inverter?

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