Filed under: Macbook Pro
MacBook Pro: Inconsistent backlight, hissing LCD [Updated x3]
I'm
almost done with my answer-your-questions MacBook Pro review. But before I post that, I thought it was appropriate to
inform you of what appear to be Rev. A glitches in most MacBook Pro models I've tested:The bottom of the LCD is noticeably brighter than the rest of the display, with a translucent white stripe (no affiliation to the band) stretching from one end to the other. Also, at the back of the bottom of the display (near the vent area) there seems to be a high-pitched hissing noise, presumably (?) emanating from the LCD (as the sound is consistent from one end of the lid to the other).
Everyone I spoke with who bought one of these new laptops also has these problems, and so did all the MacBook Pros at my local Apple Store.
Reader input time: If you have one of these suckers, are you experiencing the same LCD-inconsistency/hissy noise problems?
Click on to see a semi-poor quality image of the problem.
Update: Reader Paul makes an interesting observation: The high-pitched hissing noise, despite the consistent volume around the edge of the machine, seems to be coming from under the keyboard. And when the hard drive spins up to perform a task, it stops. I'm still testing this, but if the observation is apt then that would mean the noise is hard drive-related, and not the LCD as originally thought.
Update 2: OK, this just gets more thrilling: A hardware guru tells me that the hard drive is in the front-left of the machine, not the back by the noise, which means this is probably not a hard drive issue and could very well be the fan. Or the GPU. Or the CPU. Or even the speakers. Anyone else with any technical insights?
Update 3: Well, for me (and probably for most of you, too), the noise problem is the processor: I installed Apple's CHUD tools (located on the included OS X disk with the Xcode installer) and found in the new Processor preference pane that when I disabled the Core Duo's second core, the high-pitched hissing noise went away. A troubling problem, for sure, but if the noise is really that bad for you, you could always enable the Processor menu item and just turn off the second core when you don't need it.
See the brightness towards the bottom?
![TUAW [Cafepress]](http://www.blogsmithmedia.com/www.tuaw.com/media/tuaw-cafepress-promo.png)
Reader Comments (Page 1 of 7)
joe said 8:47PM on 2-22-2006
wow, that sucks. I am planning on buying one of these sometime in the semi-near future, but there is obviously something going on with the backlight.
I've never heard of a hissing LCD either...
I'd expect better for the amount of coin these machines are going for, especially when you are telling us that it's definitely not just your machine.
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Brian said 8:48PM on 2-22-2006
Mine is still copying over settings from my iBook. Against the gray background of the "Transfering Information" screen, I do see the brightness along the bottom edge. It's not distracting to me, though and I don't know that I would have noticed it if I hadn't read this article.
Can't hear a "hissing" noise but my tinnitus might be drowning it out. :)
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Paul said 8:52PM on 2-22-2006
I noticed it at the one at my local store, but I thought it was just the one that I was looking at. Guess not.
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Nujw said 8:56PM on 2-22-2006
I haven't noticed any issues with the display, but I have noticed the same hissing sound. At first, I thought it was emanating from the speakers, but it appears to be coming from beneath the keyboard. I also noticed that it goes away when the drive is being read. When the drive goes idle, the hissing returns.
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Graham H said 8:56PM on 2-22-2006
Revision A. Bound to have problems.
/enjoying a (now) error free Powerbook G4 15" :)
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Nujw said 8:56PM on 2-22-2006
I haven't noticed any issues with the display, but I have noticed the same hissing sound. At first, I thought it was emanating from the speakers, but it appears to be coming from beneath the keyboard. I also noticed that it goes away when the drive is being read. When the drive goes idle, the hissing returns.
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Trevor said 8:57PM on 2-22-2006
I just got mine today. It is not having either of these problems.
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John said 9:00PM on 2-22-2006
I received mine this morning, and have tried several wallpapers in an attempt to see the brightness inconsistency. None so far have revealed it. Further, as far as I can tell this MacBook is silent, or close to it. I listened to it in comparison to my 15" PB, and it seemed noticeably more quiet.
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Mr. Arnoldy said 9:06PM on 2-22-2006
I have a 15 PB with High Res screen, and it has the hissing problem as well as the popular white lines. The hissing comes from under the keyboard, thinking its the GPU. It only hisses and clicks when I'm looing at something moving on the screen, like scrolling down in a webpage, or looking at a flash movie. I guess they haven't changed the screens out yet, bummer.
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Jesse said 9:09PM on 2-22-2006
is the hissing possibly the two fans inside as show in the nekkid shots?
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Mark baseggio said 9:22PM on 2-22-2006
My first gen 17" Powerbook G4 had the hissing problem as well. This problem has been around for a long time, I suspect it is more likely noise from the GPU -- related to power consumption in some way.
I am receiving my new 2ghz macbook tomorrow, I'll report back asap! I certainly am not going to stand for the problem after paying what i did!
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Jonathan Sugai said 9:23PM on 2-22-2006
Hissing Noise on a PowerBook G4 15 inch (1.5 GHz).
I have heard my PBG4 hiss as well in a very very quiet room. It sounds like it's electrical, as if it were coming from the logic board itself (pick your component).
It happens when I perform an action such as loading a web page. If I perform a hard disk related activity, it gets drowned out by the hard drive. However, if I'm loading a web page, I can hear a hiss while it loads.
If you are in a room with ambient noise, you can't hear it. Frankly, it doesn't bother me at all. However, if the MacBook's hiss is constant, I guess that could get annoying. Is it constant or does it only occur when your computer does something?
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Bridget Samuels said 9:34PM on 2-22-2006
I got my MBP yesterday from an Apple store and I am not experiencing either of these problems. Sorry!
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Jason said 9:36PM on 2-22-2006
I have a Dell (not Core Duo) laptop that has a hissing noise when I move the optical mouse around. Seems like some sort of interference going on.
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Jimmy said 9:37PM on 2-22-2006
I played with my MBP last night for about 4 hours. I don't have that white stripe problem.
As to the hissing noise, I didn't have a problem. But... could it be the system fans? The OWC disassembly pictures show that there are 2 fans under the keyboard. They're at both ends of the hinge. The noise might be coming from them instead of the LCD backlight.
I did notice when the fans turned on, but it happened rarely during my 4 hours and wasn't loud enough to be bothersome. Course, my marble coffee table might have been acting like a giant heatsink.
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ryank said 9:41PM on 2-22-2006
I honestly hope that the brightness issue isn't that big of a deal for you guys - the only way it's noticable in that picture is because it's taken in a darkened room from an odd angle. Sure, it might be there, but is it seriously going to affect your working?
As for the hissing...since I can't hear it, I can't complain about people complaining (if that makes sense). But...hey, it comes with iTunes for a reason.
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Andrew Fee said 9:46PM on 2-22-2006
I have a 17" Rev.D Powerbook G4, and my screen is also brighter at the bottom; I assumed that this was just normal for laptop displays, as they're so much thinner than any other LCD I've seen. (it also had a strong red cast before calibration, as yours seems to be showing)
I don't know if the "hissing" is the same as the noise I get from my G4 Powerbook, but it has been on two other machines - it seems to be very slightly louder at the top-right of my machine though. If I load up iMovie HD and go to "titles" and preview "3D Spin" it changes to a "chirping" noise.
I have no idea why this happens, but I did find a fix. Put in your system disc, search for "CHUD" and install it. This adds a new "Processor" pane to system preferences. If you disable "Allow Nap" it goes away, for the most part. I have been doing this for almost a year now with my Powerbook and it has been running fine. It does not seem to have affected battery life or heat output at all.
This value resets every time you restart/shutdown your machine unfortunately, and I can't seem to find the AppleScript I had to change the default value on startup.
I have no idea if this will work on the Intel machines or not, but I hope it does.
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Ken R said 9:50PM on 2-22-2006
I don't know how much of a problem the brightness issue would be, but I've come to both hate and love hissing sounds. When I first got my iMac G5, it sounded great next to my Blueberry's high-pitched whine. But yet the fans are constantly running now, which is terrible for voice recording (time for soundsoap and an external mike :) ) This noise is almost therapeutic. But I absolutely can't stand it during long hard days while running Final Cut, etc. Those fans almost sound like a jet plane!
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chris said 9:53PM on 2-22-2006
The hissing sound is probably the same hissing sound which comes from the ipod (pick up a video ipod and listen closely). It stops when the hard drive boots up and sounds different when cueing through a song. I am guessing it is coming from the CPU/GPU when it is working.
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Tino said 9:54PM on 2-22-2006
I don't hear a hissing noise.
If I turn the brightness way up and use the default desktop background, there does appear to be a strip across the bottom of the screen where it's minutely brighter. This 'strip' for lack of a better term extends further up on each side than it does in the middle, which suggests to me that the backlight diffuser or reflector or something's attachment is not quite perfect.
It's not something that any normal person would notice with windows on the screen, but it's easily visible while watching a letterboxed movie or with anything else that puts a large patch of dark across the bottom of the screen.
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