Still Frames When Playing MVS

This was only noticeable on helicopters in the game. Instead of the normal rotating blades it seems to stop at one frame and not rotate.

What causes this problem?

Edit: All roms are verified.

PROG Board:

LS08 -Working

Char Board:

LS74 - Working
LS139 - Working
Neo-273 - Working

First time I've run into this problem.

Which game are you talking about?

Random and somewhat strange theory:

Presuming that you're not on an RGB/Arade monitor...have you tried a diferent TV/video configuration? My thought is that you might be in some sort of video scaling situation where frames get dropped. If the rotating blade is a simple enough animation, you might be left with only one frame of it left, making it seem like there's no animation at all.

Note: I realize this one seems a bit absurd. It seems like it would be something with the game/hardware, but that doesn't appear to be adding up.

Well, it turned out to be one of those rare occasions when a rom verifies but under stress it has problems. I swapped all the C roms over to a new board and the problem followed. When taking a closer look at the graphic issue, it wasn't a graphic problem but more a program problem since the graphics were clear.

Burned a new p rom and the problem went away. The old p rom still verifies 10/10 times, weird. The only other time something like this happened was on a TMNT board I had where the onboard rom test said everything was good but one of them was actually bad.