Home
Posted By: valiant66 Monitor suddenly showing weird green lines - 09/19/09 08:54 PM
Any idea why my monitor would start showing green lines? They follow along shade transitions, i.e. where a brown transitions to a gold etc. They're all over the screen, from desktop to browser windows to whatever.
Welcome aboard.

It would help to provide details of your system — ie, type/model of monitor, OS, etc.
Otherwise it's only guesswork rather than directed responses by those in the know.
Hi, and welcome to FineTunedMac. smile

> Any idea why my monitor would start showing green lines?

Try these two tests:

1. Try starting up in Safe Mode (What is Safe Boot, Safe Mode?) and see if your green lines disappear.

2. Dig out your Apple Hardware Test disc and give the (I think it's called) extended test a run-through of at least 5 loops (control-L).

Please let us know your results, and please respond to grelber's request.
Originally Posted By: grelber
Welcome aboard.


Thanks.

Originally Posted By: grelber
It would help to provide details of your system — ie, type/model of monitor, OS, etc.
Otherwise it's only guesswork rather than directed responses by those in the know.


The monitor is an Apple 30" Cinema Display "2005". The video card is an NVIDIA GeForce 7300 GT.

The Mac is a Mac Pro 3 Ghz Dual-Core Intel Xeon.

Just upgraded to Snow Leopard.
Originally Posted By: artie505
Hi, and welcome to FineTunedMac. smile


Thanks again.

Originally Posted By: artie505
> Any idea why my monitor would start showing green lines?

{snip}

Please let us know your results, and please respond to grelber's request.


Actually, before trying those tests I turned the monitor (but not the computer) off overnight. The lines were gone in the morning.

I suspect a thermal problem of some kind.

Yesterday was a hot day and the room with the computer was unusually hot. Today is a cooler day and so is the computer.

I also suspect it was the card overheating rather than the display because the screen grabs I took had the lines and screen grabs seem to grab the video signal rather than monitor.

I'm going to write this off as a "buy an air conditioner" solution.

Thanks, guys.
Originally Posted By: valiant66
I'm going to write this off as a "buy an air conditioner" solution.

Not a bad idea but in the meantime a fan to circulate the air in the room and particularly around your Mac would be a good idea. You can also verify your temperature theory with something like Marcel Bresink's Temperature Monitor
In addition to JoeMikeB's advice, you might want to check (and clean where necessary) your Mac's air vents, particularly if you haven't done so for a while. It's quite possible that accumulated dust has reduced the cooling airflow.
© FineTunedMac