CPS2 Work RAM NG

[Arcade-Projects]

I've got a CPS2 b-board which has developed a fault, boot up RAM test screen shows some garbage and 'WORK RAM NG', gets no further than that text.

I can't seem to find any mention online on just what comprises the work ram in the CPS2 system though - only mentions I see are of the 6264s being the object RAM. There don't look to be any other discrete chips which could be RAM though.

Anyone got any technical knowledge which may help? I'm guessing it might be some 74 logic chips failing, or maybe some traces, but would like to have somewhere to start from.

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