14 Replies Latest reply: Nov 11, 2008 8:46 AM by Tinieblas
Tinieblas Level 1 Level 1 (0 points)
Ok, I've found several other posts very similar to this, but none of the suggestions in them have worked. I have an iBook G4, and turning it on today I found I can barely see the screen. At first I thought it was just black, but if I look really hard, I can see that everything's there. So I've tried adjusting the display. I've tried reset the nvram. I've tried running it on battery, AC, both... nothing works. It turns on fine, and it's charging normally, I just can't see anything. Adjusting the brightness doesn't have any effect either. I turn it all the way down or up and it just stays the same. Any other suggestions that I can try would be great.

MacBook, Mac OS X (10.4.11)
  • JEichstaedt Level 1 Level 1 (0 points)
    I as well am having this problem. I can open the lid about 5 inches and I can see the screen fine. After that its very dim and you can not see anything. I ahve hooked it up to external monitor and its fine. I took it to the computer shop here at WMU and they are authorized by Apple, so they said. They have ordered parts and put them in with no luck in fixing the problem. the ordered an *Inverter board 992-5019, cable 922-6899 and lvds cable 922-6831*.

    From what I have read on here it should have fixed the problem, right? The tech told me that it could be the logic board. If that were the case wouldn't other stuff be going haywire as well? (works fine when plugged into external monitor)

    I would love to know what the next step should be or if i should just buy a new one?

    Jay
  • Tinieblas Level 1 Level 1 (0 points)
    Yeah, I'd assume that if it were the logic board it wouldn't have the view that it does, and it wouldn't work on an external... But I don't really know. I've tried about everything that I can think of, and nothing's worked so far. It's still just dark.
  • spudnuty Level 5 Level 5 (6,695 points)
    JE,
    I can open the lid about 5 inches and I can see the screen fine

    So does it just blink off at some angle of opening? If so that's probably the inverter cable.

    Tin,
    Yeah, I'd assume that if it were the logic board it wouldn't have the view that it does, and it wouldn't work on an external..

    That could be more a PMU problem. It isn't completely dark right? Just dim?
    If it's completely dark then it's the inverter cable as above. I've seen some of these iBooks with blown up super capacitors. That cap is there to hold settings on the PMU not sure what failure would mean to the operation of the PMU.

    The PMU is CMOS and as such is also very sensitive to static, which could kill it.

    Richard
  • spudnuty Level 5 Level 5 (6,695 points)
    JE,
    I can open the lid about 5 inches and I can see the screen fine

    So it dims down at a certain angle? Try opening the back and taking off the shield and see if that makes a difference. Also try pressure on the GPU.

    Tin,
    Yeah, I'd assume that if it were the logic board it wouldn't have the view that it does, and it wouldn't work on an external..

    That could be more a PMU problem. It isn't completely dark right? Just dim?
    If it's completely dark then it's the inverter cable as above. I've seen some of these iBooks with blown up super capacitors. That cap is there to hold settings on the PMU not sure what failure would mean to the operation of the PMU.

    The PMU is CMOS and as such is also very sensitive to static, which could kill it.

    Also try pressure on the GPU.

    Richard
  • Tinieblas Level 1 Level 1 (0 points)
    Yeah, it's just really dim. At first I thought it was completely dark, but if I look really close I can see things. On mine it doesn't make a difference how open it is or at what angle I look at it, it's always the same. Everything else appears to be running fine, it's just dark.

    What do you mean when you say "try pressure on the GPU"?
  • spudnuty Level 5 Level 5 (6,695 points)
    Tinieblas,
    If you can see something on the screen then the GPU ( Graphics Processor Unit ) is probably OK.
    It's probably the inverter cable (most), inverter (less) or backlight ( least ).
    Look in this same area at a post with a similar problem.
    "LCD, reed switch, invertor board?"
    and run the continuity checks on the cable.
    Richard
  • JEichstaedt Level 1 Level 1 (0 points)
    I took it to a place here at WMU and the replaced the inverter cable, inverter board and some other cable. Nothing worked. They made me pay $97 bucks for nothing. I then took it to an Apple store and a tech looked at it and said it was the backlight. How much does this cost to get fixed. They have some service and you set it up and they will fix everything that is wrong with your computer for $290. I want to know if this is around the price of a backlight problem or should I look around here (kalamazoo) for some place cheaper.

    I also tried the logic board shim fix, it did nothing at all. I guess the upside would be they could find a few other things wrong with it and fix it for that $290 price.

    Let me know what you guys think.

    JPE
  • spudnuty Level 5 Level 5 (6,695 points)
    JE,
    I as well am having this problem. I can open the lid about 5 inches and I can see the screen fine. After that its very dim and you can not see anything.

    Now that still sounds like the inverter cable. Is that still going on?
    ..authorized by Apple, so they said. They have ordered parts and put them in with no luck in fixing the problem. the ordered an Inverter board 992-5019, cable 922-6899 and lvds cable 922-6831.

    This sounds like a shotgun approach. The first thing to have done based on the first symptom (above) was a continuity test on the inverter cable.
    I don't see how a positional problem with the screen angle would be a symptom of a bad back light.
    Richard
  • JEichstaedt Level 1 Level 1 (0 points)
    Richard

    I took it to the guys he said what he thought it was, ordered those parts I listed, put them in and it still doesn't work at all. Now the screen is dark all the time. If I put a flash light on the screen I can see the stuff. My guess was that the backlight was going bad and is now has fully crapped out. One interesting thing was that one of the cords the tech gave me back had a date on it and it was 4-12-2007. Odd considering I got the laptop in October 2005. Any ideas why there is a date on there.

    What could be some other problems that might cause this. I may just stick with using the external considering I am almost done with grad. school and don't need the mobility right now and buy a new one sometime this summer.

    Thanks for the help.

    JPE
  • JEichstaedt Level 1 Level 1 (0 points)
    Richard

    Is it possible they didn't do anything at all? I read one of your posts from a different thread and it says something about how changing out an inverter board would fix it because it supplys the power to the backlight. Do backlights just burn out? Should I rip these guys a new one and try to get my money back?

    Jay
  • spudnuty Level 5 Level 5 (6,695 points)
    Jay,
    One interesting thing was that one of the cords the tech gave me back had a date on it and it was 4-12-2007.

    Wait! You're right that doesn't make sense. Is that on the LVDS or the inverter/reed cable? Does it look used? especially at the hinge point?
    I read one of your posts from a different thread and it says something about how changing out an inverter board would fix it because it supplys the power to the backlight.

    Well inverters do fail but mostly the cables fail.
    Do backlights just burn out?

    Dunno never seen one but it's sure possible.
    It's also possible that the driver on the logic board got burned out but if it was working at a shallow angle that doesn't sound right.
    Those guys that worked on your iBook shouldn't have charged you for putting in parts that didn't fix the problem. Especially if they were replacing good parts.
    Richard
  • Stanton Bond Level 1 Level 1 (35 points)
    My daughter's ibook G4 has developed a similar problem. The backlight works (Apple lights on the reverse side of the lid), but the screen is very dark (not completely dark) and doesn't display the desktop. Even when the ibook is in this condition, it will still drive an external display just fine. The angle of the lid seems to be irrelevant to the problem in our case. At best the screen flickers enough to be annoying, at worst, it goes dark. Since you can see or not see the screen on any given day, I'm guessing that whatever is wrong is in some stage of getting worse?? Why else would the problem be intermittent?

    The intermittent nature of this suggests hardware to me more than software, but I'm asking anyone who might know what to do.
  • spudnuty Level 5 Level 5 (6,695 points)
    Hi Stanton,
    Would you repost this as a seperate post. Then it can get the groups full attention.
    Off hand it sounds like a GPU problem. Try any of the shim fixes mentioned all over this board.
    I can give you a more precise location for the GPU when I know the CPU speed and screen size.
    Richard
  • Tinieblas Level 1 Level 1 (0 points)
    Completely pulled it apart along with another that was also dead and used the good parts from both to rebuild one that now works...