here are two links about what I did.
http://www.amiga.org/gallery/index.php?n=1326"When i soldered denise to the board, i knicked a line under the chip when removing the socket. It looked real minor, so i didnt bother to check up on it. Turns out that was a mistake, as video and everything else with the system is top notch, i only get horizontal mouse movement. A quck check with the probe reveals that no vert signal is going to the chip, so here is my fix for that, everything is working great now."
http://www.amiga.org/gallery/index.php?n=1325Odd, I swear I had the problem *before* I did the repair. Maybe not.