Help cps3 3-7 simms not recognized

[MostroVeneno]

Hey guys, trying to figure out what's wrong with this cps3. Cart superbios and simms work fine on other cps3 mobo.
This one doesn't recognize all simms row from 3-7 as the image shows. At least it's powering up and displays video. Is there a particular section or ic's that would handle these simms? Anyone knows if schematics for cps3 are available?

 

[KaPH33n]

I would try cleaning the simms and connectors first. Try putting the one from SIMM1 into SIMM3 and see if it sees it then?