Help File: HDMI or VGA from laptop to HDTV; a stopped Mac clock

Sunday, November 29, 2009

Q: Is there a difference in quality between HDMI and VGA when plugging a laptop into an HDTV?

A: A digital HDMI (High-Definition Multimedia Interface) cable will carry video and audio, unlike analog, video-only VGA (Video Graphics Array) cables. That alone argues for HDMI -- if your computer has that output or, with the right adapter, a DVI (Digital Visual Interface) or Mini DisplayPort connector.

But things aren't always simple when pairing computers and consumer electronics. You might think that digital is always better than analog, but VGA and HDMI connections from two laptops yielded about the same visual quality on a 40-inch LCD. And you can have issues getting the computer's desktop to fill the TV's screen in either setup.

If you want to watch a movie downloaded from a service such as Apple's iTunes that's been locked with "digital rights management" usage controls, you may have to use HDMI -- but you can still hit unexpected snags getting a computer to accept a display. HDMI can be finicky even without DRM hassles: An older Sony HDTV yielded an "Invalid format" error with each of three laptop HDMI connections.

So try to get HDMI to work, but don't feel too bad if you have to fall back to VGA.

My Mac's menu bar clock is stuck at 9:59 a.m.

This can happen when a background application in Mac OS X called SystemUIServer gets stuck. To free it up, go to the Utilities subfolder of the Applications folder, launch Activity Monitor, and type "systemui" in its search box. You should see only one result, "SystemUIServer"; select that and click the "Quit Process" button above it. The menu bar's clock and the other system-notification icons should vanish, then reappear with the current time.

Rob Pegoraro attempts to untangle computing conundrums and errant electronics each week. Send questions to The Washington Post, 1150 15th St. NW, Washington, D.C. 20071 or Visit for his Faster Forward blog.

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