Pi2jamma pinhp screen issue

[morph100]

For some reason a handful of games don’t display properly they just rotate round like this. Any ideas on how to fix?

 

[Fantazia2]

Adjust vertical sync? Dont know what video modes the pi2jamma runs but original boards would have slightly different vertical sync rates.

 

[morph100]

Only happens on some game though, but yeah looks like that, i will have a fiddle

 

[Retroman839]

them irem games …

I read They are a little bit off on the pcb’s too .. refresh is a little diffrent .
I think that’s why the issue is occurring