Did someone help you, or did an answer or User Tip resolve your issue? Upvote by selecting the upvote arrow. Your feedback helps others! Learn more about when to upvote >
Did someone help you, or did an answer or User Tip resolve your issue? Upvote by selecting the upvote arrow. Your feedback helps others! Learn more about when to upvote >
Looks like no one’s replied in a while. To start the conversation again, simply
ask a new question.
My powerbook was delivered on 24th Oct and no white spots (yet). The screen was perfect up until yesterday when I noticed a general unevenness of illumination.
The bottom corners of the screen now appear brighter and a darker patch hangs over the middle of the dock and extends about 1/3 of the way up the screen.
It's not blindingly obvious but very annoying to me, I'm just concerned it might be described as falling within normal parameters if I send the computer back.
I don't think full brightness will slow the problem, just minimize the appearance of the problem. that's just a guess though...if you have the problem i'd send it in. i've always gotten my machine back quickly and in good shape. there are those who have had things happen - if that's the case just call them IMMEDIATELY. they'll do what they can to rectify.
It's also my belief that the problem is neither halted nor delayed by keeping the screen at full brightness. What full brightness does do (at least to me anyway) is give me a headache after prolonged use. I think it may also shorten the lifespan of the screen in the long run.
As for the worry of incurring additional damage whilst in the workshop - yes, some people have reported this happening. However, my own experience is the opposite. I have not had any such problems at all.
As an alternative you might want to consider taking it to an Apple Authorised Service Provider local to you. When I took mine in to the small local AASP for a warranty hard drive replacement, I had the PB in a SleeveCase. Surprisingly they suggested I leave the SleeveCase with them as it will help protect the PB whilst it's in the workshop. I was a little sceptical but, afterwards, did think if they raised the point about protecting the PB then it had crossed their minds that customers wanted their items handled with care - and was more inclined to take better care of my PB. Plus, pyschologically, I've also put a face to my PB by taking it in myself.
I have my screen replaced in November 2004, and now my lower right side is evenly darker than other area.
And rcently one round white spot, sized 1 cm roughly, appeared about the cnter.
Problem is:
1. Mine is now out of the warranty period and I didn't buy the Apple Care Plan. (purchase date 29/3/2004
2. Mine is not included in the White Spot replacement serial number range...
At least partially, "the same problem appeared in less than 6 years (I know it is more than 90 days).
Is there anything I can try? Last time, they didn't chage the inverter (I requested it!).
I dunno JH. you should take it in to an apple store and ask about the white spot issue. that's a known defective issue that apple might replace regardless of warranty?
in my case, this is the 3rd replacement. 1st for uneven illum. second for white spots, then a third because my whole logic board died. However, apple said my 2nd replacement for the white spots wasn't a "REPAIR" request, as it's a known defect so it's free o charge?
anyways... i'm getting uneven illumination again, but i dont care anymore... it'll be my 4th problem and i'm sick and tired of dealing with it...
ALSO my boss got his screen replaced, and now the screen's viewing angle is a lot less than mine, and it's a more grey/blueish lighter now (so there's not much contrast)
what gives?
anyways, these problems all occurred within 2-3 months of each other. it's ridiculous but oh well, i'd rather deal with it than go back to my gawd awful toshiba. ALL the problems prompted me to get applecare. people should get that anyways - laptops are finicky
If you need to set your screen to pure white so as to show up defects go to System Prefs > Desktop/Screen saver > Select Solid Colours > Select empty space below column 3 vertical or same for horizontal.
Last friday, a representative of Apple called me to let me know that they are going to replace my unit which is a severe and repeatedly case of uneven illumination:
so i can't believe i'm contributing to this thread again. i had a 1.25 powerbook that had the uneven illumination problem and other glitches. after the uneven illumination returned, i called and negotiated a replacement: a 1.67.
loved the machine but darned if it didn't start up with a dark cloud over the lower right hand corner. i was really hoping the new third-generation machine would be free of the problem but no luck. i'm supposed to get it back from repair today. we'll see...
okay, i guess apple says that it's within spec. the weird thing is, the screen looks a lot better than when i sent it in. they also replaced the top assembly (trackpad/keyboard/etc) and i wonder if a connection got tightened or something. anyway, it's better now and i hope it lasts...
This UI issue is definitely "weird". Since Apple fixed it at the second attempt mine had behaved well until a few months ago when it suddenly re-appeared. Then, after a few weeks and just as I was losing my patience and prepping it for sale, it disappeared again.
Only the Almighty knows whats what with this thing. Apple, us poor souls in the middle and the PowerBooks certainly have no clue. I've given up with theories. My only strategy now is if it shows up again then it's for sale, otherwise it stays (for now).
I may have an answer to what's causing the uneven illumination problem in the Powerbook G4 Aluminum 15", and any other laptop with a similar problem.
I fix Macs (since 1985), and I've opened practically every model. However, until recently, I hadn't had anyone bring me any Powerbook G4 model for a lamp (backlight) replacement (I like to call it the "backlight", but the official term is "lamp", so I'll use that--it's the long, thin fluorescent tube that runs the length of the bottom of the display), so I couldn't get a look inside one of these displays to see what's going on. So, I'd been speculating on what's causing this uneven illumination problem (you can see my earlier posts in this discussion), but came up only with unproven and unlikely theories, such as a lamp that was darker on one side than the other, or inverter boards that were putting RF noise into one side of the lamp. I finally got a chance to directly investigate when a client brought a Titanium Powerbook G4 to me about a month ago--he had dropped his and it had broken the lamp. I took the display apart, and installed a replacement lamp, and what do you know--the uneven illumination problem showed itself. I've seen this with Titaniums, but not as bad as the Aluminum PBG4. I later asked the client if he had seen this problem before I had taken his Powerbook apart, and he confirmed that he had, so I didn't feel too bad about whether I had done something wrong. I fiddled with things, and found that the position of the reflector that the lamp sits in, is far more critical than I had realized--even a slight bending or uneven positioning of the reflector can affect illumination along the bottom of the display. This reflector is a highly polished, long rectangular piece, or channel, with one end open where it faces the clear plastic layer; the lamp sits in this reflector. It sits along the bottom edge of the display, reflecting the lamp's light up into the clear plastic sheet that transmits the light throughout the display, which then reflects off a white sheet behind the actual liquid crystal display panel. I found I could slightly twist the reflector, and cause the bright areas to dim, and vice versa. By applying hand pressure along the entire length of the reflector, thus better aligning its whole length, I was able to even out the illumination to an almost satisfactory degree. The only trick is how to maintain that amount of pressure when I reassemble the display, since I won't be following the client around to apply helpful pressure to his display.
So, the most likely theory is that the reflector that the lamp is housed within, isn't positioned exactly properly, and may be getting bent slightly over time--miniscule changes in the position of the reflector can make a big difference in illumination at the bottom of the display. Letting the lamp warm up will sometimes help, both because the lamp gets brighter, and possibly also because as the reflector warms up, it may sometimes twist back into a better position and shape. All this could explain why some people see the problem come and go, and also see the problem develop only over time, even with a replacement display. Opening and closing the display may be torquing the reflector over time.
Some people who send their Powerbook in for repair, say the repair paperwork says the inverter board was replaced, but not the LCD, but they say the illlumination has improved. I wouldn't be surprised if some Apple techs are manipulating the reflector into a better position, and replacing the inverter either with one that puts out more voltage to increase the bulb's brightness, or just to be on the safe side, or to say they replaced a part, or all three possibilities.
Even when illumination is relatively normal, you'll still often see that the left and right lower corners are dim. This is because the two ends of the lamp, about a quarter of an inch each, where the electrodes are embedded, aren't illuminated as well as the rest of the lamp, at least right after powerup. The lamp itself is as long as the display, but there's a little bit of extra room in some display models to fit in a slightly longer lamp, which would probably eliminate this problem, but it's not an easy job, especially in the Titaniums, where the display halves are glued together. This corner dimness can also sometimes disappear, like the uneven illumination along other portions of the bottom of the display, as some Powerbooks are left on, since in some Powerbooks, as the lamp warms up, it either gets bright enough to swamp the dark ends, or the dark ends eventually get to the same brightness as the rest of the lamp.
There are probably a few other causes for uneven illumination, but those are probably the primary ones.
That seems to make sense. I had my screen replaced this March, and it was working fine, but all of a sudden the issue comes up again. Outside of warrenty, which really p** me off.
Anyway.
The rationale I am developing now for the sudden appearance is the following:
I bought a 20" Cinema display a couple of weeks ago, which I have used extensively with I have used extensively with my PoBo.
PoBo with the lid closed, and even though it is situated on an iCurve, I expect that it does get hotter than in normal operation.
Where is the epic centre of this heat? Near the hinges. Where does the uneven illumination start? From the bottom of the screen, i.e. the hinges.
That seems to match admirably with your assessment.
Now my question: without doing nasty surgery: would there be a way to reverse this???
