You could try underclocking your Geforce a little, although performance will decrease it should theoretically use less power.
Also (And this is for people who know what they are doing) you can look in your bios and see if there is a setting for AGP driving control, if there is manually set it to EA.
Also (And this is for people who know what they are doing) you can look in your bios and see if there is a setting for AGP driving control, if there is manually set it to EA.