I have an iMac G5 2Ghz that when it start up you can only see video for a few seconds. I connected an external monitor and my iMac works fine but with its on LCD there is no video. I check the logic board led and the 3 are ON. I check it using the apple on line trubleshootin but aftwer that the only thing is to take it to an apple repair center. Is there any part I could buy to repair it myself I am very good as an IT

Sir,
The iMac G5 and iMac G5 (Ambient Light Sensor) computers have a video out port located on the back of the computer, which will mirror video. Video mirroring means you can see the same image that is on the iMac G5's flat-panel display on an external monitor, television, or projector.
Using the video out port, you can mirror video with a compatible VGA display using the Apple VGA Display Adapter.
You can also use the video mirroring feature with a television or projector that has S-video or composite video connectors when you use the Apple Video Adapter.
Both the Apple VGA Display Adapter (M8639G/A) and the Apple Video Adapter (M9109G/A) are available separately, and are needed if you want to use your iMac with a VGA monitor cable, S-video cable, or composite video cable.
The video mirroring feature is "plug and play". Simply connect a VGA display, television, or projector to the appropriate adapter (see above), then connect the adapter to the video out port located on the back of the computer.
When you connect the adapter to the computer, the screen may refresh momentarily as the computer prepares itself for the new video output. The computer tries to match the resolution of the built-in and external display. If there is no match, the computer changes both screen resolutions and may black out areas on the built-in display in order to match the capabilities of the external display.
Important: To ensure that your iMac G5 automatically detects the external display or projector, be sure you plug the adapter into the external display or projector before you plug it into the iMac G5.
You can switch resolutions and frequencies for both the iMac G5 flat-panel display and the external display, television, or projector using Displays preferences.
Want to watch a DVD movie disc on a television that's connected to your iMac G5? Select a 720 x 480 NTSC (in the United States) or 720 x 576 PAL (in Europe and other regions) resolution in Displays preferences.
Tip: Because of the display limitations of most televisions, the images displayed on a television screen are usually not as high quality as those on the built-in display or an external monitor.


Thanks
Good Luck