Mac mini DVI problems: Distorted Display, Loose connections (#4)

We continue coverage of DVI display problems with the Mac mini. The problem reports boil down to 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 write:

"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."

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."

Not just with minis? Meanwhile, a few readers are reporting DVI distortion issues on other Mac models. MacFixIt reader Tym writes:

"I've experienced the same type of issue with a Samsung LCD monitor connected to my 1.5GHz PowerBook G4 via DVI. It doesn't happen every day, but once in a while the LCD will go black for a second or two, and then return to normal. I haven't been able to trace what causes it. It seems to be random. The connector is very snug against the powerbook, so I don't think it's a connection issue."

Feedback? Late-breakers@macfixit.com.

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