Lines on desktop?

[rabatat]

This has just started happening – when I move a window around on my desktop, or open and close a Sticky, it is leaving behind a column of dotted lines on my desktop. These lines are now beginning to appear in my scroll bars as well. It appears to be getting worse every time I restart.

 

[chscag]

Information about your Mac? Year, model, and which version of OS X are you running?

It sounds like the LCD may be defective or failing - but that's only a guess for now until we get more info from you. By the way, that symptom you described is called "ghosting". Usually caused by a defective LCD.

 

[rabatat]

Hi – thanks for your reply.

I have a iMac G5; PowerMac8,2; Processor name: PowerPC G5 (3.0). I don't know the year, I'm afraid (I bought it second-hand about three years ago). I'm running Mac OS 10.5.8. I'm not so technically minded, so if there is more information I could provide, please let me know.

Is this condition fatal or can it be rectified?

 

[chscag]

With a machine that old, it could be a LCD defect. Ghosting typically shows up in older LCDs.

However, we will want to make sure. When you see those lines on the screen, take a screenshot of your desktop. If the same lines or ghosting shows up in the screenshot, it may be related to a defective graphics card. If not, it's the LCD. You can also test by attaching an external monitor to the G5.

 

[rabatat]

OK. I'll do that. Thank you very much for your prompt reply and your assistance.

Cheers, Rab

 

[rabatat]

Hello again – the lines DO appear on the screenshot – can the graphics card be replaced?

 

[chscag]

Your machine uses an ATI Radeon 9600 graphics chipset which is soldered on to the logic board. In order to replace it, that would require the entire logic board (mother board) to be replaced.

What you might do if you're handy with taking things apart.... Is to open up the machine and check to see if the fans and vents are clogged with dirt. Try to clear the fans and heat sinks best you can. What could be happening is that dirt might be blocking the machine from cooling properly. Overheating could well cause the graphics processor to display those symptoms.

You can get instructions for taking the machine apart at iFixit: The free repair manual.
Note that taking any model iMac apart is a fairly difficult task because generally, the display panel must be removed first before the inside of the machine is exposed.