TITLE
    Power Macintosh 8500, 8600: Unable To Display Video On TV
Article ID:
Created:
Modified: 		18559
9/8/95
9/12/00
TOPIC

    I have a Power Macintosh 8500. In addition to my computer monitor, I have attached a television to the correct ports on the back of the computer, but I cannot seem to get the video to display on the television. I get video on my computer monitor, but my television is black. What am I doing wrong?

DISCUSSION

    The situation you describe can also occur with the Power Macintosh 8600. Power Macintosh 8500 and 8600 systems can be configured with either 2 or 4 megabytes (MB) of video random-access memory (VRAM). Troubleshooting the problem depends on how much VRAM is installed in your computer.

    2 MB of VRAM
    If your Power Macintosh 8500 or 8600 system is equipped with 2 MB of VRAM, you can display video on either a computer monitor or a television, but not both at the same time. The computer detects what type of display device is attached when starting up and makes the proper adjustments. The computer defaults to the monitor when both a monitor and television are attached, hence the television screen will be black. Follow these directions to display video on a television from your computer:
      1. Make sure that your computer and television are both turned off.
      2. Disconnect your computer monitor from the video port on the back of the computer.
      3. Connect the television to the composite or S-video out connectors on the back of the computer.
      4. Turn on the television.
      5. Start up your computer.
      6. The video now appears on your television.
    If, after following these steps, there is still no image on the television, you need to make sure that the VRAM Dual Inline Memory Modules (DIMMs) are installed in the slots labelled "1" on the logic board. If the VRAM DIMMs are installed in the slots labelled "2", the video out feature does not work.

    If you want to use both the television and monitor at the same time, you need to add an additional 2 MB of VRAM to your computer. If you install additional VRAM you can also use a larger desktop, or use video mirroring for presentations and recording.

    4 MB of VRAM
    If your Power Macintosh 8500 or 8600 system is equipped with 4MB of VRAM, you can view the desktop on both the monitor and the television. If no image appears on the television, you need to open the unit and check the video cable connections.

    Troubleshooting
    Warning: Your computer contains electrically sensitive parts. To avoid damaging your computer, discharge static electricity that may be on your chest or body by touching (and maintaining contact with) the power supply case when working with the assembly. The following troubleshooting directions are provided primarily for Apple Service providers. If you attempt to perform upgrades or repairs yourself, any damage you may cause to your equipment will NOT be covered by your warranty.

    Examine the internal AV ribbon cable and make sure it is attached between the logic board and the external composite and S-video connectors on the back panel of the computer. The internal ribbon connector must be attached to the logic board for the detection circuitry to operate properly. If the cable is not connected properly, reconnect the internal cable to correct this problem.

    [These words have been added to the article to aid searching: video out video-out NTSC PAL]

Document Information
Product Area: Computers
Category: Power Macintosh
Sub Category: Power Macintosh 8500; Power Macintosh 8600

Copyright © 2000 Apple Computer, Inc. All rights reserved.