Mac Mini: DVI Problems: "Snowy" displays; loose connections

The Mac mini's DVI display problems generally fall into two categories:

• A distorted or "snowy" display that is most often triggered by playing DVDs or performing other video-intense operations
• A seemingly loose connection that causes drop-outs in video throughput, resulting in a temporarily blank screen.

Distorted "snowy" display MacFixIt reader John Edwards has posted some images that depict the distorted DVI output delivered by some Mac minis.

John writes:

"I also have had the issue with the snowy display; most notable at higher resolutions (1024x768 or higher) and most notable on black backgrounds (looks really bad with a letterbox DVD)

"I'm using a Viewsonic VP201S monitor using DVI.

New ATI firmware required? In its documentation for a ROM update available for retail Radeon 9200 graphics cards (the same model used in the Mac mini), ATI says the update resolves the following issue:

"Users may see corruption in the form of green or other colored pixels appearing to the left of windows on the finder or randomly through-out a 3D scene. The issue is not reproducible in exactly the same way for everyone. Situations where this issue may occur include: wake from sleep; systems have been running approximately 20 minutes."

Unfortunately, as noted by a handful of readers, the Mac mini does not ship with the updated firmware. Instead of version 124, which fixes the issue, the mini ships with ROM version 116.

The retail version of the firmware will not update the card that is installed in the Mac mini, so a new update will need to be released by ATI or distributed by Apple.

Loose connections We continue to receive reports of loose display connections on the Mac mini.

MacFixIt reader Lynn writes:

"I went to an Apple Reseller a couple of weeks ago and found the same issue with a Mac mini that they had set up on display, connected to a ViewSonic CRT. If you moved Mac Mini at all, the CRT would shut off. If you moved the video adapter the monitor with come on again. I looked at and felt the movement of the adapter connection and found it to be fairly loose. You could push it in for a tighter fit, but once you moved the Mac mini, it would loosen up and the CRT would cut off or quit again."

Jeff Schoch adds:

"I too am having a problem using the DVI on the Mac Mini. With several applications open and switching between the apps in the dock or opening and closing windows the screen will go black for a second and then pop back up with no warning. It seems to happen more often when opening and closing windows but has also appeared when the computer is not in use. When the computer is not in use it usually rolls the video vertically (like you use to have happen with older TVs and the vertical hold). I have changes monitors and cables but it has affected all setups that I have used. It can get very bad at times with the screen blanking out about every 10 seconds or so. I have not been able to figure out why it is doing this.

Make sure thumbscrews are tightly fastened A number of readers have noted that there are indeed thumbscrews used to fasten the Mac mini's DVI connection, but they may be difficult to locate without thorough inspection.

MacFixIt reader Greg writes:

" There are thumbscrews in the body of the adaptor itself, on the sides toward the rear. I used them myself, although it took me a minute to figure them out as there's no documentation I saw. Without them, I'd agree that the connector is easily bumped when attaching a USB cable."

Another reader writes:

"I thought the adapter couldn't be tightened also, but the adapter has the screw locks on the side. Once I tightened up the adapter, my video connection improved 100%. I was having the same problem, video going off and on when accessing any of the ports on the back of the Mini.

Finally, MacFixIt reader Knut adds:

"The mini DVI/VGA adapter does have two screws that allow it to be snugly fastened to the DVI connector on the mini just like a VGA connector. These screws are very nicely integrated into the body of the DVI/VGA adapter so they may not be so obvious (and ugly) as on a typical VGA connector. Look closely on either side of the adapter."

Resources