Turn on the PCB and try to squeeze little more the rectangle part to the PCB and look on the screen does it make it better, if there will be any noticeable change for better while doing it you will know where lies the issue, if not, try same thing with the CPU part, if it turns out that it is...
The PCB is made from 3 parts, you can detach 2 of them (plug off the white leg thingies), the big square part is CPU, the small rectangle is graphics, it holds all the graphical data of the game. Detach all of them and inspect. I suspect that there is a corrosion on the chips legs of the...
Soul Calibur II home port is most updated version but Soul Calibur III ARCADE EDITION is most recent because it came after home relase and fixed some bugs from it.
I hope it to be better than Saturn port. In Chronicles of Mystara on Xbox360 and WiiU I had 1st Place Records for some time :) I need to check where I am now on Xbox