Hi all, I am putting a 12" Alum 1.5 Ghz PB back together after very reluctantly needing to take it apart (DC-In Board problem). There is some white hardened thermal paste on the CPU which I am cleaning off with isopropyl alcohol and will be replacing with arctic silver for reattachment to the heatsink. My problem lies with the GPU and the system controller/northbridge chip(s). They both had a blue thermal pad between them and the heatsink. So do I a) Remove these and put thermal paste directly on these chips instead? b) Replace these both with new thermal pads? c) Re-use the existing thermal pads? I have a read an opinion elsewhere about a possible gap between the heatsink and these chips if paste is used instead of thermal pads. Should I use paste for the CPU then and pads for the other chips? Or is this nonsense? Thanks very much in advance!