CPS2 AVP ILLEGAL INST screen issue

[Arcade-Projects]

Hi all, I've just purchased an Alien VS Predator A and B board which has a fault on start up. The logo comes up and it starts to show the pre game back story which is then interrupted by red text showing the following in the picture attached. Any help would be appreciated as this is my first CPS2 board and it was sold as working which it clearly isn't.

Ben

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