I've encountered the "rolling line" display issue on a couple WPC-95 games, as described here:
Otherwise, I haven't needed to replace any other significant WPC-95 driver board caps yet. I suspect that might start changing in the next few years as they get older.
For WPC-89 driver boards...I've seen issues all over the map. Sometimes caps are involved, sometimes not.
Quoted from ChrisHibler:PROVING that the cap was the issue would be nearly impossible. You'd have to remove and replace the cap "in-situ", which isn't possible.
I usually test removed caps with an Atlas ESR70. If the cap is way off spec, then I figure it's usually a good indicator that it was contributing to a problem.
I'll also test the new caps going in to make sure they aren't duds or counterfeits.
