You must remember that most DVD recorders were consumer devices, operated by people that smoked, used the DVD tray as a cup holder, and for kids to stick LEGO in. Always expected ES10/15 to be abused, and be pleasantly surprised when it actually properly works -- aka, another reason to opt for actual TBCs, not ES10/15 type, etc.
These units are now 18+ years old (came out in 2005), and many have been "rode hard and put away wet". When a unit fails to function, just return it.
There's no magic or special settings to the ES10/15. Turn it on, properly wire IN to VCR and OUT to capture card, set to proper output on remote, and that's it. If that fails to work, return it.
There are lots of potential problems with the units, and you'll often see all of them. Again, consumer devices, often operated by hamfisted goons and grubby kids.