Like most DVD devices seem to be, this is a computer-type DVD drive with a front end--probably running some variant of Linux--to control it. The drive has a typical ATA (AKA IDE, EIDE, or PATA) interface and would plug right into a typical computer without any fuss.
The defective drive mechanism is Lite-On's model DDW-813s. You can, apparently, get Lite-On's model DH-20A3P drive mechanism, which will work well in place of the failed one.
And I found it on PriceWatch for $28 plus S&H. So maybe I won't need a new DVD recorder just yet.
Since it's 2 AM on Sunday, I'm going to try going to Best Buy later today to see if they have something that'll work; and even if they don't, I've been thinking about buying another drive anyway, so I'll see if the new one will pop into the DVD recorder.
The other possibility is that the drive in this computer--which is a Lite-On drive I pulled out of my P3 when I upgraded--may work, too. It's a Lite-On SOHW-1673S.
I tried disassembling the drive mechanism thoroughly and then reassembling it, but that didn't fix it. Sometimes--sometimes--you can resurrect a CD-ROM drive by doing that. I've done it many times. But I guess the problem here is something to do with the high-frequency laser, because while the drive will play CDs just fine, any DVD sends back "Invalid Disk". *sigh*
And right now I'm making an SVCD of the first three eps of Doujin Work which--I expect--will work. So it's the DVD part of the drive which has crapped out. *sigh*
Maybe the replacement drive will be more durable.