[michael180]

I am currently on a Mac Pro. I use an Apple 30" cinema display monitor. It's exhibiting some green noise bars intermittently, sometimes so bad it's impossible to work with. I need to determine if it's the monitor or the computer that's causing these noise spikes. I would like to connect my MacBook pro to the monitor. What sort of cabling would I need. I've been to the Apple support site, but I can't find what I'm looking for.

Any suggestions?

[jamillion]

What generation Macbook Pro do you have? If it's the unibody version, you'll need to grab the $99 MiniDisplayPort to Dual-Link DVI adapter located here. If it's the older aluminum MacBook Pro, you should be able to connect it directly to the monitor.

If you're near an Apple Retail Store, take your gear there and have them diagnose it for free. That way you can be sure what the problem is, and if you need to replace anything, you'll walk out with an estimate.

I say it's the graphics card, perhaps bad VRAM or a failed GPU fan. Does the problem get worse when you run intensive 3D apps?

[michael180]

My MacBook pro is the newer model. And I will have to get the new cable.

It gets bad when it goes into the sleep mode and the screen saver comes on. As I said it's intermittent, but lately it's gotten much worse.

I'm about 25 miles from the nearest Apple store. I don't know whether to take the monitor in or the box?

I suppose I'll need to take them both. I called Apple help as I have Apple care on the Mac Pro.

Thanks . . .

[mduell]

The $99 MDP-DLDVI adapter is pretty lousy... I had all sorts of noise issues with one.

[Waragainstsleep]

Which Mac Pro/GPU do you have? There is at least one card which is prone to bulging caps. You might be able to see that if you look. I think it was the nVidia 7300GT which was prone to bad caps.
If you can see bulging, then Applecare might ship you a replacement direct as its a user serviceable part.

If you can't see any bulging on the caps, it might still be failing but just not that bad yet. You did say it was intermittent. I would advise stressing the graphics card to try to recreate the symptom. Pick an intensive graphical benchmark and run it on a loop. Or load up a (recent) game and crank up the resolution and effects. Failing that, you might be able to loop a graphics card test using the Apple Hardware Test disc that came with the machine. (Some of them have the diagnostic built-in, boot up holding D). I forget exactly what options you have access to with the AHT.
Stressing the GPU by working it hard should cause it to fail more often/quickly if the card is failing. If the noise gets worse or more frequent, the GPU is on its way out and Apple should replace it. Again, advance replacement should be doable.

[olePigeon]

For only $61.18 each when QTY 50+ purchased - Mini DisplayPort + USB to Dual-Link DVI Adapter | Mini DisplayPort to HDMI / DVI / VGA Adapters

This adapter is only $67. Monoprice is the cheapest place I've found for cables and adapters... and now toner.