As part of dropping our cable television subscription recently, I purchased a Mini-DVI to Video Adapter for my 12-inch PowerBook so we could watch DVDs on our TV (that's right - we've somehow ended up with DVD drives in multiple Macs without ever having purchased a normal consumer DVD player for our TV). It's a $20 cable, and seemed like an easy thing to order from the Apple Online Store, which was offering free shipping at the time. (Normally I'd order from Small Dog, but I needed an iBook battery too, and they were out of stock on that item at the time.)
The adapter arrived, and I plugged it into my PowerBook and into the S-video cable that had previously been used by the TiVo to send a video signal to the TV. However, when I woke up the PowerBook, expecting a picture to appear on the TV, I was disappointed - just static. Then followed two hours of troubleshooting, completely rewiring all our video devices (which needed doing anyway, given that I'd given back the cable box and could disconnect the TiVo's IR blaster and the external Supra modem I'd used to replace a blown modem in the TiVo). But no matter what I did in terms of settings in the Display preference pane, using different cables (both RCA and S-video), and adjusting the TV's settings, the best I could coax from the Mini-DVI to Video Adapter was a highly compressed, skewed, black-and-white image that was replicated three times.
I asked some savvy friends and all basically said, "It should just work," although Alan Oppenheimer, who's paying a lot of attention to display devices now that his company produces the Envision Internet slide show program, pointed me toward the shareware program DisplayConfigX, which lets you adjust the resolution and refresh rates of your video signal to match your monitor in an optimal fashion. He had good luck with using DisplayConfigX to drive a large LCD HDTV that wasn't working otherwise. Unfortunately, DisplayConfigX states fairly clearly that it doesn't support standard TV output.
Luckily, Contributing Editor Mark Anbinder lives nearby and has a 12-inch PowerBook, a Mini-DVI to Video Adapter, and a different TV. So I went over to his house, plugged my PowerBook into his adapter and TV, and it worked perfectly. I then put my adapter into the mix instead, and saw exactly the same problem as at home. Case closed - my adapter was just broken. (As an aside, troubleshooting by replacing parts of any system is one of the best possible ways to narrow down the potential causes of a problem. Keep that in mind whenever you're experiencing trouble.)
The story has a happy ending. Although it's not spelled out all that clearly on the Apple Web site, you have to call AppleCare to return a product purchased from the Apple Online Store. I did so, and after a brief frustration with an automated phone system that wanted me to say the name of the product I was having trouble with (the system interpreted "Mini-DVI to Video adapter" as "DVD Studio Pro"), I finally was able to talk with a tech support rep. Thankfully, he didn't argue with my testing, and after confirming a few things on the order, he sent me over to a customer service rep. She tapped at her keyboard for a minute or so, and then told me that she would be sending me a new adapter via two-day shipment and that I didn't have to return the broken one. That made perfect sense - it was a $20 part, and all Apple would do is throw it out.
The moral of the story? Sometimes hardware is just broken. And unfortunately, when that happens, you can waste hours trying to figure out exactly what's wrong. But kudos to Apple for solving the real problem quickly and efficiently once I knew what was wrong.
Oh, and the new adapter? It arrived, I plugged it in to the PowerBook and the TV, and it just worked. Like Macs are supposed to.