Can I reuse thermal paste from a week ago?

I just fixed a ylod ps3 (1st gen) last week with the heat gun method and reapplying thermal paste with arctic silver 5 but it just got it again. Granted i did play it pretty much nonstop. So im going back in for another try. Do i need to use more paste on the whole thing, or just the chips that are getting heated on the motherboard and not the fan?

Any advice from you ps3 wizards would be much appeciated!