Hi everione, I have this interesting situation thats driving me nuts. I bought a Flashpoint II 620 Monolight strobe unit and here is the problem. The unit has a sync cord plug and also a photocell so it can be set off by another flash. Well no matter what I tried I can't fire the unit with my D100 using the sync cord, for which I had to buy an adapter that fits into the shoe on top of the camera. I believe its called an AS-15 since Nikon failed to put a plug right on the camera. I tried all kinds of setting on the camera, bought a new sync cord etc but nothing works. Here is the interesting part, however I can fire the strobe using a second strobe to set it off through the photocell and my D100 will fire that using the same sync cords. To eliminate that it might be a strobe/cord problem I tried using one of my old Nikon F2 cameras and it fires the Monolight. So I'm at a total loss. I would like to be able to fire the unit without having a second strobe set it off. Could it possibly be the current it takes to fire the unit and the D100 not working with it? Any suggestions? I called Adorama where I bought it and they are of no help. So if anyone has an answer I would appreciate it.