14 Replies Latest reply: Nov 1, 2006 4:31 PM by Ronda Wilson
mjprigge Level 1 (0 points)
We have an old iBook that we use for presentations with a projector, and it recently stopped being able to send signal to the projector. If we boot the iBook with the projector attached, the initial grey screen with the Apple logo appears. When it switches to the blue background, the projector says "no signal." In the Displays preferences, the main display is called "Television" and it gives choices of different resolutions and MHz. (It should be "Color LCD" and without the MHz values.) The projector does not show up as a display.

Thinking that it surely was a software problem, I booted the bad iBook off a good iBook G3/500's HD (in target disk mode) and the same symptoms appeared. It is not a connection problem since the adaptor works fine when plugged into the other iBook. Zapping PRAM and resetting the PMU did not remedy the problem.

Does anyone have any ideas? Could a short circuit (perhaps in the wires going through the hinge) be confusing the display detection?


iBook G3/500   Mac OS X (10.4.8)  
  • Ronda Wilson Level 8 (41,205 points)
    Hi, Mike. Welcome to Apple Discussions.

    Try creating a new administrative account and see if the same problem occurs with a new user.
  • mjprigge Level 1 (0 points)
    Thanks for helping out. When I booted from the other iBook's hard drive, I logged in as a user on that computer. (It again detected the display as "Television" suggesting to me that it was a hardware problem.) Earlier, I also tried booting with OS 9. It didn't work, but can't remember the details. Is there another reason to make a new account?
  • Ronda Wilson Level 8 (41,205 points)
    Try going to Users > YourShortUserName > Library > Preferences and drag the com.apple.systempreferences.plist to the Desktop. Restart.

    You will have to reset your preferences, but you may regain the other settings in the Displays preferences.
  • mjprigge Level 1 (0 points)
    Deleting the systempreferences.plist file didn't fix the problem. It still detects the LCD display as a "Television."
  • infinite vortex Level 7 (21,405 points)
    What does you iBook think it is if you connect a standard display? Also, did you check your cable(s) for bent pins etc and/or change your cable(s)
  • mjprigge Level 1 (0 points)
    I haven't tried a regular moniter, but the projector and adaptor worked perfectly with the other iBook (same model). I can try a monitor tomorrow to make sure.
  • mjprigge Level 1 (0 points)
    I hooked up a 17" LCD display, and it behaved exactly the same as the projector: when booted, the gray screen with the Apple logo showed on both displays, then the external display went black as the iBook display switched to the subsequent blue-background screen. The external display was no longer detectable.

    Is there a way to bypass the attached LCD for the external? I was not able to wake the closed iBook from sleep using an external keyboard like I could with my old TiBook. I read somewhere that this is disabled on iBooks because they cool through their keyboards.
  • Ronda Wilson Level 8 (41,205 points)
    Apple doesn't say why, but they do say not to run with the lid closed:


    Is the OS 9 installation still available to you? If so, you could try booting into OS 9 and see if the problem happens there, too. If so, it's a hardware issue.
  • Douglas McLaughlin Level 9 (63,745 points)
    Disconnect any video adapter you may have attached and restart the iBook. You may need to use the Apple-control-power button to do this if you can't see a menu. At the chime, hold down on the Apple-option-p-r keys all at the same time. Wait until you have heard the startup chime for the third time, then let go of the keys. (I realize you said that zapping the PRAM didn't help, but let's give a go one more time. You did not indicate, specifically, that the video adapter was not plugged in at the time.) Does the iBook screen return to the main display at 1024 x 768? If not, you almost certainly have a hardware issue. I don't suppose it's possible that someone has installed the firmware hack that allows the extended Desktop?

  • mjprigge Level 1 (0 points)
    Although I was very skeptical, doing this fixed it...temporarily. After resetting the PRAM, the Displays preference pane came up as Color LCD. I put it to sleep, plugged in the projector, woke it, and that worked too. After telling everyone that it was fixed, I put it to sleep, disconnected the projector, woke it up, and then it had gone back to thinking it was a Television display. It still didn't detect the LCD correctly after restarting it. I was going to reset the PRAM again, but missed the start-up chime. (Another weirdness of this iBook is that the Start-up chime doesn't sound through the external speakers, only throught the head phone jack...at least some times.) After it booted the second time, miraculously, it again detected the LCD.

    I know that for the second reboot the screen was opened around 90° but I don't remember how far it was opened the first time. Hopefully, the first reboot was a fluke and there is not a short in the LCD cords going through the hinge. (I suspect that my personal iBook G3/500 has come down with the dreaded cords-through-the-hinge problems where things go haywire if it is opened 90° of more (screen flickers, I lose WiFi connections, and my trackpad occasionally stops responding). The part arrived today.)
  • jona'fro666 Level 1 (25 points)
    is the projector plugged into the mini-DVI socket (thats the rectangulr one) or the A/V socket (the one you plug speakers into) because I regurarly use my iBokk with a TV through the A/V socket, it shows up as television in system preferences, maybe the iBokk thinks that the projector is a TV and the projector doesn't see it
  • mjprigge Level 1 (0 points)
    Actually, the LCD was showing up as a Television even if nothing was connected. Today is the first test to see if the fix suggested in the previous response sticks.
  • mjprigge Level 1 (0 points)
    It acually turned out that there is something wrong with the A/V port. Everything works when headphones are plugged into the A/V port, but the computer thinks a television is connected otherwise. Until your post, I never realized that the headphone port also serves as a video-out port. Thanks! I don't see anything lodged in the hole that could be causing the problem, so we'll just keep headphones handy.
  • Ronda Wilson Level 8 (41,205 points)
    Thanks for letting us know what the problem was. It may help someone else.