Sounds like the JPAC. Not to say there's anything wrong with it, but I've found there's a kind of curve in understanding the jumper part of it. Also, different versions (as in, when they were released) have different features, for example the old one I have won't allow above VGA at all, whereas newer versions can handle at least up to XGA. Try taking off the 31Khz jumper and see what it shows.