Posted 11 February 2009 - 04:54 PM
You don't say what brands/models the power supplies are but having a higher wattage rating doesn't neccessarily make the 750w psu better.
When it comes to PSU's there is a lot more involved then just the wattage rating.
Unless the old PSU is faulty put it back in & see if the problem improves.
nVidia shows a 400W or up PSU is needed for the 8800 GT so your 530W PSU should handle it & possibly supply enough power where it's needed.
OCZ StealthXstream 700W,Gigabyte GA-EP45-UD3R , E8500, Arctic Freezer Pro 7, 3GB G.Skill PC8500,Gigabyte Radeon HD 4850 OC [1GB ], Seagate 250GB SATA II X2 in RAID 0, Samsung SATA DVD burner.