Got this board as fully working

I immediately noticed some problems on the sprites

 

Transparent objects and shadows were solid and some sprites had glitches

Konami maskroms are known to be unreliable so I ran immediately the maskrom test reveling that rom @25g was faulty.

 

Before desoldering I checked also the custom underneath which sometims has pins lifted but it was good.

Upon a close inspection I saw some rust on 3 pins of the maskrom @25g which in my opinion could be the reason of the fault

 

Therefore I decided to desolder it and resolder a 27c160 programmed with the correct file

 

 

 

 

Board 100% fixed