Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

Reidan

macrumors regular
Original poster
Apr 12, 2012
123
24
Hi. Long Time No Post!! Until recently, everything has been fine for my MBA. So I have not had a need to post here. But I do come by frequently and read the Front Page Articles and occasionally browse the forums. But, now I have an issue that has brought me back here to throw myself on the mercy of the forums. I would like to get some help please.

My 2011 MBA 11" has started flashing the screen brightness. Goes dim and bright. Can change as often as about once every 1 or 2 seconds. Will do it for awhile, then stop and act normal again.

I disabled the Auto Dim Feature a long time ago. But honestly, have not checked it recently to make sure it has not come back on. I will do that tonight when I get home.

The dimming seems almost like the change that happens when you connect, or disconnect, the power cable. But, the charging indicator is not going off and on with the change in brightness. The battery stays fully charged. I have 2 power supplies, and it has happened with both of them.

I have wiggled and jiggled the magsafe connector and it does not cause the problem. So does not seem to be the magsafe socket.

Moving the LCD back and forth does not cause it either. So does not seem to be an internal cable issue either.

About the only thing I can think of that is common when it happens is that I have been watching online videos or flash animations and the CPU fan has been running fast. So it may be an overheat issue.

Any other ideas or suggestions you can give?
 

nutjob

macrumors 65816
Feb 7, 2010
1,030
508
Hi. Long Time No Post!! Until recently, everything has been fine for my MBA. So I have not had a need to post here. But I do come by frequently and read the Front Page Articles and occasionally browse the forums. But, now I have an issue that has brought me back here to throw myself on the mercy of the forums. I would like to get some help please.

My 2011 MBA 11" has started flashing the screen brightness. Goes dim and bright. Can change as often as about once every 1 or 2 seconds. Will do it for awhile, then stop and act normal again.

I disabled the Auto Dim Feature a long time ago. But honestly, have not checked it recently to make sure it has not come back on. I will do that tonight when I get home.

The dimming seems almost like the change that happens when you connect, or disconnect, the power cable. But, the charging indicator is not going off and on with the change in brightness. The battery stays fully charged. I have 2 power supplies, and it has happened with both of them.

I have wiggled and jiggled the magsafe connector and it does not cause the problem. So does not seem to be the magsafe socket.

Moving the LCD back and forth does not cause it either. So does not seem to be an internal cable issue either.

About the only thing I can think of that is common when it happens is that I have been watching online videos or flash animations and the CPU fan has been running fast. So it may be an overheat issue.

Any other ideas or suggestions you can give?

The backlight may be worn out or faulty. A fluorescent tube tends to flicker and change brightnesses when it goes out.
 

motrek

macrumors 68030
Sep 14, 2012
2,613
305
The backlight may be worn out or faulty. A fluorescent tube tends to flicker and change brightnesses when it goes out.

MBA backlights have all been LED to my knowledge.

Still, the power electronics that power the LEDs might be wearing out.
 

Reidan

macrumors regular
Original poster
Apr 12, 2012
123
24
Yes, that is what I have been fearing is happening. I know in older laptops there was a high voltage driver board that ramped up the voltage to drive the fluorescent bulbs. You could swap out that small part to fix it. But, like you said. Modern Day laptops use LED's for the back light. So they are most likely just a small single component on the system board.
 

nutjob

macrumors 65816
Feb 7, 2010
1,030
508
MBA backlights have all been LED to my knowledge.

Still, the power electronics that power the LEDs might be wearing out.

It still might be the backlight, that would be an early-ish LED backlight and may be failing prematurely. Of course that would be pretty much indistinguishable from the associated power circuitry failing.
 

Reidan

macrumors regular
Original poster
Apr 12, 2012
123
24
It still might be the backlight, that would be an early-ish LED backlight and may be failing prematurely. Of course that would be pretty much indistinguishable from the associated power circuitry failing.

I would think that if the LED themselves were failing, the screen would go completely dark. IE, you could still see a picture on the screen with an external source, but it would have no light behind it to make it visible. But this just dims down. As if unplugging the power and it dims the LED's to conserve power.
 

Reidan

macrumors regular
Original poster
Apr 12, 2012
123
24
Yeah!!! I sweet talked my boss into buying me a new MacBook. :D

He had promised me a reward for completing a year long project early and under budget. He asked what I wanted and I jokingly said a new MacBook, thinking he would say no. He said yes!!

I had asked for one as my work laptop before, and he did say no to that. Said that if other employees see me with it, then they will also want one. But, he considers this to be a gift. So he said yes. But, I am sure I will be expected to take it home and not bring it back to work once I get it. That is fine with me!!! :cool:

So, now I do not need to worry about repairing my old 2011 for this screen flickering issue. I just need it to last a little longer until I get the replacement to come in.

I am thinking the top of the line 2015 13" Retina with the 2.9 Ghz CPU and the 512 Gb Flash. And order it with the 16 Gb of RAM upgrade. I know that gets it into the price range of the bottom line 15". But, I think the 13" size is what I want. And the ram and storage should do me well for the life of this MacBook.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.