iMac G5 w/ ALS has strange display issue

I have an iMac G5 with Ambient Light Sensor with a strange video peoblem. The image below is a screen capture of the desktop. As you can see, there are faint lines and boxes showing throughout the display. These appear no matter what application is running or whether an image is still or moving, as in a video. Everything else with the computer works fine. I have recently replaced the video inverter with no effect. The capacitors are all working with no bulges or leaks. I've booted in Safe Mode; the shapes are still there, although they look a little different, more faded. I have used an adaptor to connect the machine to a projector; the shapes appear on the projected image, so it's not just a faulty display. I am now officially stumped. Has anyone else out there encountered a similar problem or have any idea what is causing this?

G'day and welcome to the forums. Shame it has to be in poor circumstances.

Looks like graphic card problems and this is not replaceable in an iMac. It is part of the logic board.

I just replaced the logic board and the problem still exits. Is it likely that the problem could exist on two logic boards? The guy I bought the 2nd board from said it was tested and working. I'm thinking it's something other than the video chip. But I could be wrong.

Okay, the strangest thing has happened. The display has cleared! All on it's own, too. I brought in to the classroom where I teach and plugged it in figuring that, even with the faulty display, students could make movies and music. After two days, I came in one morning and the display was clear. here's another strange thing; I had received the Steve Jobs biography for Christmas and brought it to school to put on the book shelf for others. It wound up on the same desk as the iMac. Could Steve Jobs be influencing Macs even from the beyond?

It wound up on the same desk as the iMac. Could Steve Jobs be influencing Macs even from the beyond?

Click to expand...

You never know. Maybe we need to contact Mulder and Scully and get them on this right away. ;P