i have two DDR2 512mb memory sticks but one doesn't show?

Question

i have 1gb memory .

2 x 512mb

one works fine and shows 512mb memory, where did the other one go?

thanks

Answer 1

are they both ddr?
are they both the same kind of megahertz?
it might be the one chip isn't fully seated and not detecting correctly.
swap the 2 chips over and see if its the ramslot itself that isnt faulty. blow hard into the ram slots before you seat the chips to make sure theres nothing in the slots preventing conductivity.
when you boot up does it detect 512 or 1gig?