I know this is an old post but it may help someone. Interesting that they'd say 9-12V. It will probably work, but this is what I know about car electronics. I'm a product design and electrical engineer and I've developed lots of products that plug into car cigarette lighter sockets. The 12V power is really "noisy" meaning there are spikes and jolts and surges all over the place. It's a nominal 13.5V on most electrical systems, though the newer cars with advanced electronics may clean that up a bit. But here's the deal: The "nominal" (average) already exceeds their 9-12V spec, and when you consider the spikes and surges, I'd think you'd be risking blowing out your DVD unit to plug it in with a direct 12V cord.
The 9V cord not only transforms it down to a lower input voltage, but it has a switching regulator that adapts very quickly to quell spikes and surges. The replacement adapter from Philips is $12, but hey, that already fried! It probably didn't "fry itself", but more likely was fried by the car you used it in which may have had worse surges than the average car. I would get the $20 one from Radio Shack (m/n 273-369). Take in your player to a store and they'll fix you up with the correct tip in the right configuration. I'm not insensitive to your need for economy, but you are risking frying your whole $130 DVD player for want of $10 or $20 for a good power cord. Go without those Lattes for a week and get a quality power cord.
Good information. I later emailed Panasonic about the question and they were kind enough to send me a replacement for free. When I got the new one I opened the old one and guess what? No circuitry at all inside. So it's taking the variable voltage straight out of the lighter socket. And I saw the malfunction... One of the solder joints had broke and made a disconnect. Duh.
answered on May 22, 2012