Thanks for the replies
I meant to update this thread as a forum member here sent me a link to this RDRAM datasheet (Not necessarily the exact same brand of RDRAM used in the N64, but it does have the same pinout):-http://www.datasheetcatalog.org/datashe ... 718C50.pdf
The bottom of page 4 does seem to confirm that they are just 'mechanical support pins'
Also found this picture in an old thread in these forums:-
Seems to show they are not connected to anything at all.
The strange thing is on PAL N64's these pins are connected to +3.3V, if you look carefully at a PAL motherboard you can see the +3.3V trace connecting to the pins. I dont know if this difference is because im comparing 'RDRAM18-NUS A' to RDRAM-NUS B', if its a PAL/NTSC difference, or if the motherboard design was simply improved in the year or so difference between the revisions.
Anyway, I soldered the pins back down that didnt have a ripped pad and the N64 still works fine, so please consider this sorted
Thanks for everyones help