Help fixing an old Ibanez 7 string s7420

[nuno81291]

Hello, my friend has a 2 humbucker, 5 way (with 7 lugs) 1 volume 1 tone (presumably completely stock) Ibanez s7420 he brought over to figure out whats wrong.. I am sort of puzzled with this 5 way switch and none of the diagrams I am finding online correspond to the Schaller 5 way/ 7 lugs + ground switch... The neck pickup has a Red/Black/Green/White leads, the bridge only has a red and white leads. I am unsure what the pickups are (took them off and couldnt find a makers mark or model # etc, so presumably stock...) Perhaps someone here is familiar with the switch or the guitar configuration and could help me sort this one out. I am quite baffled as I sit with my multimeter. The serial # indicates it is a 99' year model if that helps at all..